Running Literature - Dr. Nick's Running Blog

The literature on running shoes and injuries is to date inconclusive in regards to treat or prevention. It is apparent that for the past 40 years injuries have actually risen and a collection of literature from the Cochrane Data base has demonstrated the current treatment strategies for overuse soft tissue injuries are not successful. Below is the literature supporting the aforementioned statement.

Med Sci Sports Exerc. 2014 Feb 4.

Running Shoes Increase Achilles Tendon Load in Walking: an Acoustic Propagation Study.

Wearing SC(1), Reed L, Hooper SL, Bartold S, Smeathers JE, Brauner T.

Author information:
(1)1Institute of Health and Biomedical Innovation, Queensland University of
Technology, Brisbane, Australia. 2Centre of Excellence for Applied Sport Science
Research, Queensland Academy of Sport, Brisbane, Australia 3University of
Melbourne, Melbourne, Australia 4Faculty of Sports and Health Sciences,
Technische Universität München, München, Germany.

BACKGROUND: Footwear remains a prime candidate for the prevention and
rehabilitation of Achilles tendinopathy as it is thought to decrease tension in
the tendon through elevation of the heel. However, evidence for this effect is
equivocal.
PURPOSE: This study used an acoustic transmission technique to investigate the
effect of running shoes on Achilles tendon loading during barefoot and shod
walking.
METHODS: Acoustic velocity was measured in the Achilles tendon of twelve
recreationally-active males (age, 31±9 years; height, 1.78±0.06 m; weight,
81.0±16.9 kg) during barefoot and shod walking at matched self-selected speed
(3.4±0.7 km/h). Standard running shoes incorporating a 10-mm heel offset were
used. Vertical ground reaction force and spatiotemporal parameters were
determined with an instrumented treadmill. Axial acoustic velocity in the
Achilles tendon was measured using a custom built ultrasonic device. All data
were acquired at a rate of 100 Hz during 10s of steady-state walking. Statistical
comparisons between barefoot and shod conditions were made using paired t-tests
and repeated measure ANOVAs.
RESULTS: Acoustic velocity in the Achilles tendon was highly reproducible and was
typified by two maxima (P1, P2) and minima (M1, M2) during walking. Footwear
resulted in a significant increase in step length, stance duration and peak
vertical ground reaction force compared to barefoot walking. Peak acoustic
velocity in the Achilles tendon (P1, P2) was significantly higher with running
shoes.
CONCLUSIONS: Peak acoustic velocity in the Achilles tendon was higher with
footwear, suggesting that standard running shoes with a 10-mm heel offset
increase tensile load in the Achilles tendon. Although further research is
required, these findings question the therapeutic role of standard running shoes
in Achilles tendinopathy.

PMID: 24500535 [PubMed – as supplied by publisher]
Int J Sports Phys Ther. 2012 Oct;7(5):525-32.

Changes in lower extremity movement and power absorption during forefoot striking and barefoot running.

Williams DS 3rd, Green DH, Wurzinger B.

PURPOSE/BACKGROUND: Both forefoot strike shod (FFS) and barefoot (BF) running
styles result in different mechanics when compared to rearfoot strike (RFS) shod
running. Additionally, running mechanics of FFS and BF running are similar to one
another. Comparing the mechanical changes occurring in each of these patterns is
necessary to understand potential benefits and risks of these running styles. The
authors hypothesized that FFS and BF conditions would result in increased
sagittal plane joint angles at initial contact and that FFS and BF conditions
would demonstrate a shift in sagittal plane joint power from the knee to the
ankle when compared to the RFS condition. Finally, total lower extremity power
absorption will be least in BF and greatest in the RFS shod condition.
METHODS: The study included 10 male and 10 female RFS runners who completed
3-dimensional running analysis in 3 conditions: shod with RFS, shod with FFS, and
BF. Variables were the angles of plantarflexion, knee flexion, and hip flexion at
initial contact and peak sagittal plane joint power at the hip, knee, and ankle
during stance phase.
RESULTS: Running with a FFS pattern and BF resulted in significantly greater
plantarflexion and significantly less negative knee power (absorption) when
compared to shod RFS condition. FFS condition runners landed in the most
plantarflexion and demonstrated the most peak ankle power absorption and lowest
knee power absorption between the 3 conditions. BF and FFS conditions
demonstrated decreased total lower extremity power absorption compared to the
shod RFS condition but did not differ from one another.
CONCLUSIONS: BF and FFS running result in reduced total lower extremity power,
hip power and knee power and a shift of power absorption from the knee to the
ankle.
CLINICAL RELEVANCE: Alterations associated with BF running patterns are present
in a FFS pattern when wearing shoes. Additionally, both patterns result in
increased demand at the foot and ankle as compared to the knee.

PMCID: PMC3474309
PMID: 23091785 [PubMed]

US Army Med Dep J. 2012 Oct-Dec:25-30.

Relationships among self-reported shoe type, footstrike pattern, and injury
incidence.

Goss DL(1), Gross MT.

Author information:
(1)US Army-Baylor University Doctoral Program in Physical Therapy, Fort Sam Houston,
Texas, USA.

CONTEXT: Some runners are experimenting with barefoot or minimalist shoe running
to reduce lower extremity overuse injuries. However, there has been little
research to examine injury trends associated with barefoot or minimalist shoe
running.
OBJECTIVE: To assess the association of self-reported shoe selection with
reported foot strike patterns, compare overall injury incidence associated with
different shoe conditions, and identify differences in injury location between
different shoe conditions.
DESIGN: Retrospective descriptive epidemiology survey.
METHODS: We recruited 2,509 runners (1,254 male, 1,255 female) aged 18 to 50 to
complete an anonymous online survey. The survey assessed running tendencies,
footstrike patterns, shoe preferences, and injury history. Reported footstrike
patterns were compared among 3 shoe groups: traditionally shod, minimalist shoes,
and barefoot runners. Overall and specific anatomical injury incidence was
compared between traditionally shod and minimalist shoe-wearing runners. We did
not include 1,605 runners in the analyses due to incomplete data or recent
changes in footstrike patterns and/or shoe selection.
RESULTS: Shoe selection was significantly associated with reported footstrike (χ²
(4df) =143.4, P<.001). Barefoot and minimalist runners reported a more anterior
footstrike than traditionally shod runners. Traditionally shod runners were 3.41
times more likely to report injuries than experienced minimalist shoe wearers
(46.7% shod vs 13.7% minimalist, χ² (1df) =77.4, P<.001, n=888). Minimalist shoe
wearers also reported fewer injuries at the hip, knee, lower leg, ankle, and foot
than traditionally shod runners.
CONCLUSION: Barefoot and minimalist shoe wearers reported a more anterior
footstrike than traditionally shod runners. Traditionally shod runners were more
likely to report injuries of the lower extremities than runners who wear
minimalist shoes. Additional longitudinal prospective research is required to
examine injury incidence among various footstrike patterns and shoe preferences.

PMID: 23007933 [PubMed – indexed for MEDLINE]

Knee. 2012 Jun;19(3):163-75. doi: 10.1016/j.knee.2011.05.013. Epub 2011 Jul 5.

Effect of footwear on the external knee adduction moment – A systematic review.

Radzimski AO(1), Mündermann A, Sole G.

Author information:
(1)Center for Physiotherapy Research, University of Otago, P.O. Box 56, Dunedin, New
Zealand.

CONTEXT: Footwear modifications have been investigated as conservative
interventions to decrease peak external knee adduction moment (EKAM) and pain
associated with knee osteoarthritis (OA).
OBJECTIVE: To evaluate the literature on the effect of different footwear and
orthotics on the peak EKAM during walking and/or running.
METHODS: A systematic search of databases resulted in 348 articles of which 33
studies were included.
RESULTS: Seventeen studies included healthy individuals and 19 studies included
subjects with medial knee OA. Quality assessment (modified Downs and Black
quality index) showed an (average±SD) of 73.1±10.1%. The most commonly used
orthotic was the lateral wedge, with three studies on the medial wedge. Lateral
wedging was associated with decreased peak EKAM in healthy participants and
participants with medial knee OA while there is evidence for increased peak EKAM
with the use of medial wedges. Modern footwear (subjects’ own shoe, “stability”
and “mobility” shoes, clogs) were likely to increase the EKAM compared to
barefoot walking in individuals with medial knee OA. Walking in innovative shoes
(“variable stiffness”) decreased the EKAM compared to control shoes. Similarly,
shoes with higher heels, sneakers and dress shoes increased EKAM in healthy
individuals compared to barefoot walking.
CONCLUSIONS: Further development may be needed toward optimal footwear for
patients with medial knee OA with the aim of obtaining similar knee moments to
barefoot walking.

PMID: 21733696 [PubMed – indexed for MEDLINE]

Hum Mov Sci. 2012 Feb;31(1):182-9. doi: 10.1016/j.humov.2011.06.004. Epub 2011

Aug 12.

Ground reaction force adaptations during cross-slope walking and running.

Damavandi M(1), Dixon PC, Pearsall DJ.

Author information:
(1)Department of Kinesiology and Physical Education, McGill University, Montreal,
QC, Canada H2W 1S4. mohsen.damavandi@mcgill.ca

Though transversely inclined (cross-sloped) surfaces are prevalent, our
understanding of the biomechanical adaptations required for cross-slope
locomotion is limited. The purpose of this study was to examine ground reaction
forces (GRF) in cross-sloped and level walking and running. Nine young adult
males walked and ran barefoot along an inclinable walkway in both level (0°) and
cross-slope (10°) configurations. The magnitude and time of occurrence of
selected features of the GRF were extracted from the force plate data. GRF data
were collected in level walking and running (LW and LR), inclined walking and
running up-slope (IWU and IRU), and down-slope (IWD and IRD), respectively. The
GRF data were then analyzed using repeated measures MANOVA. In the
anteroposterior direction, the timing of the peak force values differed across
conditions during walking (p=.041), while the magnitude of forces were modified
across conditions for running (p=.047). Most significant differences were
observed in the mediolateral direction, where generally force values were up to
390% and 530% (p<.001) larger during the cross-slope conditions compared to level
for walking and running, respectively. The maximum force peak during running
occurred earlier at IRU compared to the other conditions (p≤.031). For the normal
axis a significant difference was observed in the first maximum force peak during
walking (p=.049). The findings of this study showed that compared to level
surfaces, functional adaptations are required to maintain forward progression and
dynamic stability in stance during cross-slope walking and running.

PMID: 21840076 [PubMed – indexed for MEDLINE]

Clin Biomech (Bristol, Avon). 2012 Jan;27(1):27-33. doi:

10.1016/j.clinbiomech.2011.07.010. Epub 2011 Sep 8.

Lateral wedge insoles for medial knee osteoarthritis: effects on lower limb frontal plane biomechanics.

Hinman RS(1), Bowles KA, Metcalf BB, Wrigley TV, Bennell KL.

Author information:
(1)Centre for Health, Exercise and Sports Medicine, Physiotherapy, School of Health
Sciences, The University of Melbourne, Victoria, Australia. ranash@unimelb.edu.au

BACKGROUND: Lateral wedges reduce the peak knee adduction moment and are
advocated for knee osteoarthritis. However some patients demonstrate adverse
biomechanical effects with treatment. Clinical management is hampered by lack of
knowledge about their mechanism of effect. We evaluated effects of lateral wedges
on frontal plane biomechanics, in order to elucidate mechanisms of effect.
METHODS: Seventy three participants with knee osteoarthritis underwent gait
analysis with and without 5° lateral wedges. Frontal plane parameters at the
foot, knee and hip were evaluated, including peak knee adduction moment, knee
adduction angular impulse, center of pressure displacement, ground reaction
force, and knee-ground reaction force lever arm.
FINDINGS: Lateral wedges reduced peak knee adduction moment and knee adduction
angular impulse (-5.8% and -6.3% respectively, both P<0.001). Although reductions
in peak moment were correlated with more lateral center of pressure (r=0.25,
P<0.05), less varus malalignment (r values 0.25-0.38, P<0.05), reduced
knee-ground reaction force lever arm (r=0.69, P<0.01), less hip adduction
(r=0.24, P<0.05) and a more vertical frontal plane ground reaction force vector
(r=0.67, P<0.001), only reduction in knee-ground reaction force lever arm was
significantly predictive in regression analyses (B=0.056, adjusted R(2)=0.461,
P<0.001).
INTERPRETATION: Lateral wedges significantly reduce peak knee adduction moment
and knee adduction angular impulse. It seems a reduced knee-ground reaction force
lever arm with lateral wedges is the central mechanism explaining their
load-reducing effects. In order to understand why some patients do not respond to
treatment, future evaluation of patient characteristics that mediate wedge
effects on this lever arm is required.

PMID: 21862189 [PubMed – indexed for MEDLINE]

Comput Methods Biomech Biomed Engin. 2012;15(5):467-74. doi:

10.1080/10255842.2010.542153. Epub 2011 May 24.

Pattern classification of kinematic and kinetic running data to distinguish gender, shod/barefoot and injury groups with feature ranking.

Eskofier BM(1), Kraus M, Worobets JT, Stefanyshyn DJ, Nigg BM.

Author information:
(1)Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500
University Dr NW, Calgary, AB T2N 1N4, Canada. bmeskofi@ucalgary.ca

The identification of differences between groups is often important in
biomechanics. This paper presents group classification tasks using kinetic and
kinematic data from a prospective running injury study. Groups composed of
gender, of shod/barefoot running and of runners who developed patellofemoral pain
syndrome (PFPS) during the study, and asymptotic runners were classified. The
features computed from the biomechanical data were deliberately chosen to be
generic. Therefore, they were suited for different biomechanical measurements and
classification tasks without adaptation to the input signals. Feature ranking was
applied to reveal the relevance of each feature to the classification task. Data
from 80 runners were analysed for gender and shod/barefoot classification, while
12 runners were investigated in the injury classification task. Gender groups
could be differentiated with 84.7%, shod/barefoot running with 98.3%, and PFPS
with 100% classification rate. For the latter group, one single variable could be
identified that alone allowed discrimination.

PMID: 21294006 [PubMed – indexed for MEDLINE]

Foot Ankle Surg. 2011 Dec;17(4):218-23. doi: 10.1016/j.fas.2010.07.003. Epub 2010

Sep 17.

The influence of shoe sole’s varying thickness on lower limb muscle activity.

Ramanathan AK(1), Parish EJ, Arnold GP, Drew TS, Wang W, Abboud RJ.

Author information:
(1)Institute of Motion Analysis & Research, Department of Orthopaedic & Trauma
Surgery, TORT Centre, Ninewells Hospital & Medical School, University of Dundee,
Dundee, DD1 9SY, Scotland, UK.

BACKGROUND: The lateral ligament injury of the ankle is acknowledged to be the
most common ankle injury sustained in sport. Increased peroneus longus muscle
contraction in the shod population has already been documented. This study aimed
to quantify the effect of shoe sole’s varying thickness on peroneus longus muscle
activity.
METHODS: Electromyographic recordings of the peroneus longus muscle activity
following unanticipated inversion of the foot from 0° to 20° in a two-footplate
tilting platform were collected from 38 healthy participants. The four test
conditions were: barefoot, standard shoe, and shoes with 2.5 cm and 5 cm sole
adaptation respectively.
RESULTS: Compared to the barefoot condition, there is an increase in the
magnitude of muscle contraction on wearing shoes, which further increases with
thickening shoe soles. The peroneus longus was responding earlier in the shod
conditions when compared to the barefoot, although the results were variable
within the three shod conditions.
CONCLUSION: Footwear with increasing shoe sole thickness evokes a correspondingly
stronger protective eversion response from the peroneus longus to counter the
increasing moment at the ankle-subtalar joint complex following sudden foot
inversion. Hence, fashion footwear with thicker sole is likely to increase the
risk of lateral ligament injury of the ankle when such protective response is
overwhelmed. Similarly, the clinicians need to be cautious regarding the amount
of shoe raise that they could provide for patients with limb length discrepancy
without any detrimental untoward side effects.

PMID: 22017890 [PubMed – indexed for MEDLINE]

Knee. 2011 Dec;18(6):407-11. doi: 10.1016/j.knee.2010.07.011. Epub 2010 Aug 24.

Shod landing provides enhanced energy dissipation at the knee joint relative to barefoot landing from different heights.

Yeow CH(1), Lee PV, Goh JC.

Author information:
(1)Department of Orthopaedic Surgery, National University of Singapore, Singapore.

Athletic shoes can directly provide shock absorption at the foot due to its
cushioning properties, however it remains unclear how these shoes may affect the
level of energy dissipation contributed by the knee joint. This study sought to
investigate biomechanical differences, in terms of knee kinematics, kinetics and
energetics, between barefoot and shod landing from different heights. Twelve
healthy male recreational athletes were recruited and instructed to perform
double-leg landing from 0.3-m and 0.6-m heights in barefoot and shod conditions.
The shoe model tested was Brooks Maximus II. Markers were placed on the subjects
based on the Plug-in Gait Marker Set. Force-plates and motion-capture system were
used to capture ground reaction force (GRF) and kinematics data respectively.
2×2-ANOVA (barefoot/shod condition×landing height) was performed to examine
differences in knee kinematics, kinetics and energetics between barefoot and shod
conditions from different landing heights. Peak GRF was not significantly
different (p=0.732-0.824) between barefoot and shod conditions for both landing
heights. Knee range-of-motion, flexion angular velocity, external knee flexion
moment, and joint power and work were higher during shod landing (p<0.001 to
p=0.007), compared to barefoot landing for both landing heights. No significant
interactions (p=0.073-0.933) were found between landing height and barefoot/shod
condition for the tested parameters. While the increase in landing height can
elevate knee energetics independent of barefoot/shod conditions, we have also
shown that the shod condition was able to augment the level of energy dissipation
contributed by the knee joint, via the knee extensors, regardless of the tested
landing heights.

PMID: 20797866 [PubMed – indexed for MEDLINE]

Scand J Med Sci Sports. 2011 Dec;21(6):804-8. doi:
10.1111/j.1600-0838.2010.01116.x. Epub 2010 May 12.

Can orthotic insoles prevent lower limb overuse injuries? A randomized controlled trial of 228 subjects.

Mattila VM(1), Sillanpää PJ, Salo T, Laine HJ, Mäenpää H, Pihlajamäki H.

Author information:
(1)Centre of Military Medicine, Lahti, Finland. ville.mattila@uta.fi

Lower limb overuse injuries are common among people who are exposed to physical
stress. Orthotic shoe insoles are widely used to prevent lower limb overuse
injuries. Here, we conducted a randomized-controlled study to examine whether the
use of orthotic insoles prevents lower limb overuse injuries. Participants
(n=228) were randomly assigned to use (n=73) or not to use (n=147) orthotic
insoles. The insoles were molded to the shape of the foot to provide support
during physical activity. The main outcome measure in the present study was the
physician-diagnosed lower limb overuse injury. Thirty-four (46.6%) subjects in
the insole group were diagnosed with a lower limb overuse injury compared with 56
(38.1%) in the control group (P=0.29) during the 6-month study period. When body
mass index and the results of a 12-min running test and muscle strength were
adjusted in a Cox’s regression model, the hazard ratio for lower limb overuse
injury in the insole group was 1.3 (95% confidence intervals: 0.8-2.1) compared
with the control group. Use of orthotic insoles was not associated with a
decrease in lower limb overuse injuries. Our findings suggest that routine use of
orthotic insoles does not prevent physical-stress-related lower limb injuries in
healthy young male adults.

PMID: 20492587 [PubMed – indexed for MEDLINE]

Foot (Edinb). 2011 Sep;21(3):129-32. doi: 10.1016/j.foot.2010.12.004. Epub 2011
Jan 19.

Do foot orthoses replicate the static longitudinal arch angle during mid stance in walking?

Burn H(1), Branthwaite H, Chockalingam N, Chevalier TL, Naemi R.

Author information:
(1)Faculty of Health, Staffordshire University, Leek Road, Stoke on Trent ST4 2DF,
UK.

INTRODUCTION: In a normal clinical environment, foot function and treatment
efficacy is evaluated using static foot posture assessment. Whilst there are
several methods of static assessment, the longitudinal arch angle (LAA) has been
validated as a repeatable and reliable static measure that represents foot
posture during midstance whilst walking and running. The main aim of this study
was to assess if static LAA is representative of dynamic LAA with the use of
orthoses.
METHOD: 17 male subjects with a mean age of 33.4 (SD 12.3) years, mean height of
169.88 (SD 9.2) mm and a mean weight of 72.71 (SD 11.36)kg, who provided an
informed consent were included in the study. Orthotic prescription was produced
using measurements from a weightbearing goniometer. An optoelectronic movement
analysis system was employed to record and analyse the LAA in barefoot, shoe and
shoe with orthoses conditions. This data was collected in a static standing
condition and then repeated whilst walking.
RESULTS: No significant differences were observed between right static and right
dynamic barefoot condition t=1.329 (p=0.05). Same results were observed for right
static and right dynamic orthotic condition t=-.233 (p=0.05). Similarly, no
significant differences were recorded for left static and left dynamic barefoot
condition and orthotic condition t=.303 (p=0.05) and t=.049 (p=0.05)
respectively. However, differences were observed within the shoe only condition.
CONCLUSION: LAA is been shown to be a good static measure for dynamic foot
function and can reliably be implemented in a normal clinical environment to
evaluate and assess the efficacy of the prescribed foot orthoses.

PMID: 21251808 [PubMed – indexed for MEDLINE]

J Sports Med Phys Fitness. 2011 Sep;51(3):401-8.

Effect of a five-toed minimal protection shoe on static and dynamic ankle
position sense.

Squadrone R(1), Gallozzi C.

Author information:
(1)Institute of Sport Medicine and Sport Science, Italian Olimpic National Comitee,
Rome, Italy.

AIM: The main aim of this study was to test the hypothesis that the
VibramFivefingers model, with its minimal structure, cushioning and finger
separation, allows a more accurate estimate of static and dynamic foot position
compared to wearing a standard cushioned running shoe.
METHODS: Static ankle joint position sense was assessed in the sagittal and
frontal plane by asking fourteen healthy experienced amateur runners to estimate
the perceived direction and amplitude of a support slope surface board placed
under their right foot while standing. The dynamic measures were performed with
the subjects running on a treadmill at 12 km/h and asking them to evaluate the
treadmill surface slope. Two footwear (Fivefingers and a cushioned protective
running shoe) and the barefoot condition were compared.
RESULTS: Plantarflexion, dorsiflexion, eversion and inversion movements were
underestimated in all the experimental conditions. In the static trials there was
significantly more angle error underestimation (P<0.05) with the running shoe,
while no significant differences were found between Fivefingers and barefoot
condition. While running, the treadmill surface slope was significantly better
estimated with Fivefingers than in the other two conditions (P<0.05).
CONCLUSION: The data support the assumption that with Fivefingers is more likely
to get a more correct estimation of the surface slope while standing and running
compared to using a standard cushioned running shoe. The finding that the
cushioned shoes significantly impair foot position awareness compared to less
structured shoes is consistent with the results of some previous studies on
healthy and unhealthy subjects.

PMID: 21904278 [PubMed – indexed for MEDLINE]

J Sports Sci. 2011 Sep;29(12):1287-92. doi: 10.1080/02640414.2011.591416. Epub
2011 Jul 13.

Intravascular haemolysis during prolonged running on asphalt and natural grass in long and middle distance runners.

Janakiraman K(1), Shenoy S, Sandhu JS.

Author information:
(1)College of Physiotherapy, Cherraan’s Institute of Health Sciences, Physiotherapy,
Coimbatore, India. kamalccpt@gmail.com

Surface features such as uneven playing surfaces, low impact absorption capacity
and inappropriate friction/traction characteristics are connected with injury
prevalence whereas force impact during foot strike has been suggested to be an
important mechanism of intravascular haemolysis during running. We aimed to
evaluate intravascular haemolysis during running and compare the effect of
running on two different types of surfaces on haemolysis. We selected two
surfaces (asphalt and grass) on which these athletes usually run. Participants
were randomly assigned to group A (asphalt) or group B (grass) with 10 athletes
in each group. Each athlete completed one hour of running at the calculated
target heart rate (60-70%). Venous blood samples were collected before and
immediately after running. We measured unconjugated bilirubin (UBR) (mg ·
dl(-1)), lactate dehydrogenase (LDH) (μ · ml(-1)), haemoglobin (g · l(-1)) and
serum ferritin (ng · ml(-1)) as indicators of haemolysis. Athletes who ran on
grass demonstrated an increase in the haematological parameters (UBR: P < 0.01,
LDH: P < 0.05) when compared to athletes who ran on asphalt (UBR: P < 0.05, LDH:
P = 0.241). Our findings indicate that intravascular haemolysis occurs
significantly after prolonged running. Furthermore, we conclude that uneven grass
surface results in greater haemolysis compared to asphalt road.

PMID: 21751854 [PubMed – indexed for MEDLINE]
Orthopedics. 2011 Jul 7;34(7):e320-3. doi: 10.3928/01477447-20110526-25.

Barefoot-simulating footwear associated with metatarsal stress injury in 2 runners.

Giuliani J(1), Masini B, Alitz C, Owens BD.

Author information:
(1)eller Army Hospital, West Point, New York, USA.

Stress-related changes and fractures in the foot are frequent in runners.
However, the causative factors, including anatomic and kinematic variables, are
not well defined. Footwear choice has also been implicated in contributing to
injury patterns with changes in force transmission and gait analyses reported in
the biomechanical literature. Despite the benefits of footwear, there has been
increased interest among the running community in barefoot running with proposed
benefits including a decreased rate of injury. We report 2 cases of metatarsal
stress fracture in experienced runners whose only regimen change was the adoption
of barefoot-simulating footwear. One was a 19-year-old runner who developed a
second metatarsal stress reaction along the entire diaphysis. The second case was
a 35-year-old ultra-marathon runner who developed a fracture in the second
metatarsal diaphysis after 6 weeks of use of the same footwear. While both stress
injuries healed without long-term effects, these injuries are alarming in that
they occurred in experienced male runners without any other risk factors for
stress injury to bone. The suspected cause for stress injury in these 2 patients
is the change to barefoot-simulating footwear. Runners using these shoes should
be cautioned on the potential need for gait alterations from a heel-strike to a
midfoot-striking pattern, as well as cautioned on the symptoms of stress injury.

PMID: 21717998 [PubMed – indexed for MEDLINE]

Br J Sports Med. 2011 Jul;45(9):715-21. doi: 10.1136/bjsm.2009.069849. Epub 2010
Jun 27.

The effect of three different levels of footwear stability on pain outcomes in women runners: a randomised control trial.

Ryan MB(1), Valiant GA, McDonald K, Taunton JE.

Author information:
(1)Allan McGavin Sports Medicine Centre, University of British Columbia, Vancouver,
Canada. mryan76@gmail.com

BACKGROUND: The present study examines the injury status in women runners who are
randomised to receive a neutral, stability or motion control running shoe.
METHODS: 81 female runners were categorised into three different foot posture
types (39 neutral, 30 pronated, 12 highly pronated) and randomly assigned a
neutral, stability or motion control running shoe. Runners underwent baseline
testing to record training history, as well as leg alignment, before commencing a
13-week half marathon training programme. Outcome measures included number of
missed training days due to pain and three visual analogue scale (VAS) items for
pain during rest, activities of daily living and with running.
RESULTS: 194 missed training days were reported by 32% of the running population
with the stability shoe reporting the fewest missed days (51) and the motion
control shoe (79) the most. There was a significant main effect (p<0.001) for
footwear condition in both the neutral and pronated foot types: the motion
control shoe reporting greater levels of pain in all three VAS items. In neutral
feet, the neutral shoe reported greater values of pain while running than the
stability shoe; in pronated feet, the stability shoe reported greater values of
pain while running than the neutral shoe. No significant effects were reported
for the highly pronated foot, although this was limited by an inadequate sample
size.
CONCLUSION: The findings of this study suggest that our current approach of
prescribing in-shoe pronation control systems on the basis of foot type is overly
simplistic and potentially injurious.

PMID: 20584759 [PubMed – indexed for MEDLINE]

J Orthop Res. 2011 Jul;29(7):1042-6. doi: 10.1002/jor.21328. Epub 2011 Feb 24.

Soft tissue thickness under the metatarsal heads is reduced in older people with toe deformities.

Mickle KJ(1), Munro BJ, Lord SR, Menz HB, Steele JR.

Author information:
(1)Biomechanics Research Laboratory, University of Wollongong, Northfields Avenue,
Wollongong, New South Wales 2522, Australia. kmickle@uow.edu.au

The purpose of this study was to determine whether thickness of the plantar soft
tissue (ST) under the metatarsal heads (MTH) differed between older individuals
with and without toe deformities. Non-weightbearing total ST and fat pad (FP)
thickness at the heel, 1st metatarsal head (1MTH) and 5th metatarsal head (5MTH)
were measured using ultrasound in 312 men and women aged over 60 years. Each
participant had their feet assessed for the presence of hallux valgus or lesser
toe deformities. Total ST and FP thicknesses in those with hallux valgus (n=36)
or lesser toe deformities (n=72) were compared to gender-, age- and BMI-matched
controls using independent t-tests. Individuals with hallux valgus had
significantly reduced total ST thickness under 1MTH compared to controls
(7.4 ± 1.6 mm vs. 8.5 ± 1.5 mm; p = 0.002). Similarly, individuals with lesser
toe deformities displayed significantly reduced total ST thickness under 5MTH
compared to controls (5.1 ± 1.0 mm vs. 5.5 ± 1.3 mm; p = 0.01). As FP thickness
did not differ between cases and controls, we speculate that the musculotendinous
complex is compromised, and may result in reduced toe function in those with toe
deformities.

PMID: 21567451 [PubMed – indexed for MEDLINE]

Int J Sports Med. 2011 Jun;32(6):401-6. doi: 10.1055/s-0030-1265203. Epub 2011
Apr 6.

Oxygen cost of running barefoot vs. running shod.

Hanson NJ(1), Berg K, Deka P, Meendering JR, Ryan C.

Author information:
(1)Health, Physical Education and Recreation, University of Nebraska at Omaha,
United States. njhanson@gmail.com

Comment in
Int J Sports Med. 2012 Mar;33(3):249; author reply 250.

The purpose of this study was to investigate the oxygen cost of running barefoot
vs. running shod on the treadmill as well as overground. 10 healthy recreational
runners, 5 male and 5 female, whose mean age was 23.8±3.39 volunteered to
participate in the study. Subjects participated in 4 experimental conditions: 1)
barefoot on treadmill, 2) shod on treadmill, 3) barefoot overground, and 4) shod
overground. For each condition, subjects ran for 6 min at 70% vVO (2)max pace
while VO (2), heart rate (HR), and rating of perceived exertion (RPE) were
assessed. A 2 × 2 (shoe condition x surface) repeated measures ANOVA revealed
that running with shoes showed significantly higher VO (2) values on both the
treadmill and the overground track (p<0.05). HR and RPE were significantly higher
in the shod condition as well (p<0.02 and p<0.01, respectively). For the
overground and treadmill conditions, recorded VO (2) while running shod was 5.7%
and 2.0% higher than running barefoot. It was concluded that at 70% of vVO (2)max
pace, barefoot running is more economical than running shod, both overground and
on a treadmill.

PMID: 21472628 [PubMed – indexed for MEDLINE]

BMJ. 2011 May 18;342:d2912. doi: 10.1136/bmj.d2912.

Lateral wedge insoles for medial knee osteoarthritis: 12 month randomized controlled trial.

Bennell KL(1), Bowles KA, Payne C, Cicuttini F, Williamson E, Forbes A, Hanna F,
Davies-Tuck M, Harris A, Hinman RS.

Author information:
(1)Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy,
University of Melbourne, Parkville, 3010 VIC, Australia. k.bennell@unimelb.edu.au

Comment in
BMJ. 2011;342:d2860.
J Physiother. 2011;57(3):195.

OBJECTIVE: To assess the effect of lateral wedge insoles compared with flat
control insoles on improving symptoms and slowing structural disease progression
in medial knee osteoarthritis.
DESIGN: Randomised controlled trial.
SETTING: Community in Melbourne, Australia.
PARTICIPANTS: 200 people aged 50 or more with clinical and radiographic diagnosis
of mild to moderately severe medial knee osteoarthritis.
INTERVENTIONS: Full length 5 degree lateral wedged insoles or flat control
insoles worn inside the shoes daily for 12 months.
MAIN OUTCOME MEASURES: Primary symptomatic outcome was change in overall knee
pain (past week) measured on an 11 point numerical rating scale. Primary
structural outcome was change in volume of medial tibial cartilage from magnetic
resonance imaging scans. Secondary clinical outcomes included changes in measures
of pain, function, stiffness, and health related quality of life. Secondary
structural outcomes included progression of medial cartilage defects and bone
marrow lesions.
RESULTS: Between group differences did not differ significantly for the primary
outcomes of change in overall pain (-0.3 points, 95% confidence intervals -1.0 to
0.3) and change in medial tibial cartilage volume (-0.4 mm(3), 95% confidence
interval -15.4 to 14.6), and confidence intervals did not include minimal
clinically important differences. None of the changes in secondary outcomes
showed differences between groups.
CONCLUSION: Lateral wedge insoles worn for 12 months provided no symptomatic or
structural benefits compared with flat control insoles. Trial registration
Australian New Zealand Clinical Trials Registry ACTR12605000503628 and
ClinicalTrials.gov NCT00415259.

PMCID: PMC3100910
PMID: 21593096 [PubMed – indexed for MEDLINE]

J Am Podiatr Med Assoc. 2011 May-Jun;101(3):231-46.

Barefoot running claims and controversies: a review of the literature.

Jenkins DW(1), Cauthon DJ.

Author information:
(1)Arizona School of Podiatric Medicine, College of Health Sciences, Midwestern
University, Glendale, AZ 85308, USA. djenki@midwestern.edu

BACKGROUND: Barefoot running is slowly gaining a dedicated following. Proponents
of barefoot running claim many benefits, such as improved performance and reduced
injuries, whereas detractors warn of the imminent risks involved.
METHODS: Multiple publications were reviewed using key words.
RESULTS: A review of the literature uncovered many studies that have looked at
the barefoot condition and found notable differences in gait and other
parameters. These findings, along with much anecdotal information, can lead one
to extrapolate that barefoot runners should have fewer injuries, better
performance, or both. Several athletic shoe companies have designed running shoes
that attempt to mimic the barefoot condition and, thus, garner the purported
benefits of barefoot running.
CONCLUSIONS: Although there is no evidence that either confirms or refutes
improved performance and reduced injuries in barefoot runners, many of the
claimed disadvantages to barefoot running are not supported by the literature.
Nonetheless, it seems that barefoot running may be an acceptable training method
for athletes and coaches who understand and can minimize the risks.

PMID: 21622635 [PubMed – indexed for MEDLINE]

Gait Posture. 2011 Apr;33(4):640-4. doi: 10.1016/j.gaitpost.2011.02.010. Epub
2011 Mar 21.

Inter-segment foot kinematics during cross-slope running.

Dixon PC(1), Tisseyre M, Damavandi M, Pearsall DJ.

Author information:
(1)Department of Kinesiology and Physical Education, McGill University, Montreal,
QC, Canada. philippe.dixon@mail.mcgill.ca

Cross-slopes are a common terrain characteristic, however there is no
biomechanical knowledge of the intra-foot adaptations required for running on
these surface inclinations. The purpose of this study was to evaluate the
kinematic changes induced within the foot while running on a transversely
inclined surface. A three-segment foot model distinguishing between the hindfoot,
forefoot, and hallux was used for this purpose. Nine healthy experienced male
runners volunteered to perform level (0°) and cross-slope (10°) running trials
barefoot at a moderate speed. Multivariate analysis of variance (MANOVA) for
repeated measures was used to analyze the kinematics of the hindfoot with respect
to tibia (HF/TB), forefoot with respect to hindfoot (FF/HF), and hallux with
respect to forefoot (HX/FF) during level running (LR), incline running up-slope
(IRU), and incline running down-slope (IRD) conditions. In the sagittal plane,
the FF/HF angle showed greater dorsiflexion at peak vertical force production
(MaxFz) in IRD compared to LR (p=0.042). The HX/FF was significantly more
extended during IRU than LR at foot strike (p=0.027). More importantly, frontal
plane asymmetries were also found. HF/TB angles revealed greater inversion at
foot strike followed by greater eversion at MaxFz for IRU compared to IRD
(p=0.042 and p=0.018, respectively). For the FF/HF angle, maximum eversion was
greater during IRD than LR (p=0.035). Data suggests that running on cross-slopes
can induce substantial intra-foot kinematic adaptations, whether this represents
a risk of injury to both recreational and professional runners remains to be
determined.

PMID: 21420865 [PubMed – indexed for MEDLINE]

Gait Posture. 2011 Mar;33(3):350-5. doi: 10.1016/j.gaitpost.2010.09.019. Epub
2011 Jan 19.

Lower limb joint kinetics in walking: the role of industry recommended footwear.

Keenan GS(1), Franz JR, Dicharry J, Della Croce U, Kerrigan DC.

Author information:
(1)Department of Physical Medicine and Rehabilitation, University of Virginia,
Charlottesville, VA, USA.

The effects of current athletic footwear on lower extremity biomechanics are
unknown. The aim of this study was to examine the changes, if any, that occur in
peak lower extremity net joint moments while walking in industry recommended
athletic footwear. Sixty-eight healthy young adults underwent kinetic evaluation
of lower extremity extrinsic joint moments while walking barefoot and while
walking in current standard athletic footwear matched to the foot mechanics of
each subject while controlling for speed. A secondary analysis was performed
comparing peak knee joint extrinsic moments during barefoot walking to those
while walking in three different standard footwear types: stability, motion
control, and cushion. 3-D motion capture data were collected in synchrony with
ground reaction force data collected from an instrumented treadmill. The shod
condition was associated with a 9.7% increase in the first peak knee varus
moment, and increases in the hip flexion and extension moments. These increases
may be largely related to a 6.5% increase in stride length with shoes associated
with increases in the ground reaction forces in all three axes. The changes from
barefoot walking observed in the peak knee joint moments were similar when
subjects walked in all three footwear types. It is unclear to what extent these
increased joint moments may be clinically relevant, or potentially adverse.
Nonetheless, these differences should be considered in the recommendation as well
as the design of footwear in the future.

PMID: 21251835 [PubMed – indexed for MEDLINE]

J Biomech. 2011 Feb 24;44(4):774-9. doi: 10.1016/j.jbiomech.2010.10.041. Epub
2010 Nov 19.

The natural frequency of the foot-surface cushion during the stance phase of running.

Kim W(1), Tan J, Veloso A, Vleck V, Voloshin AS.

Author information:
(1)Biomechanics Laboratory, Faculty of Human Kinetics, Technical University of
Lisbon, Estrada da Costa, 1495-688 Cruz Quebrada, Portugal. wangdokim@fmh.utl.pt

Researchers have reported on the stiffness of running in holistic terms, i.e. for
the structures that are undergoing deformation as a whole rather than in terms of
specific locations. This study aimed to estimate both the natural frequency and
the viscous damping coefficient of the human foot-surface cushion, during the
period between the heel strike and the mid-stance phase of running, using a
purposely developed one degree-of-freedom inverted pendulum state space model of
the leg. The model, which was validated via a comparison of measured and
estimated ground reaction forces, incorporated a novel use of linearized and
extended Kalman filter estimators. Investigation of the effect of variation of
the natural frequency and/or the damping of the cushioning mechanism during
running, using the said model, revealed the natural frequency of running on said
foot-surface cushion, during the stance phase, to lie between 5 and 11 Hz. The
“extended Kalman filter (EKF)” approach, that was used here for the first time to
directly apply measured ground forces, may be widely applicable to the
identification process of combined estimation of both unknown physiological state
and mechanical characteristics of the environment in an inverse dynamic model.

PMID: 21093865 [PubMed – indexed for MEDLINE]

Phys Ther Sport. 2011 Feb;12(1):30-5. doi: 10.1016/j.ptsp.2010.08.001. Epub 2010
Sep 15.

A comparison in the muscle activity of the abductor hallucis and the medial longitudinal arch angle during toe curl and short foot exercises.

Jung DY(1), Kim MH, Koh EK, Kwon OY, Cynn HS, Lee WH.

Author information:
(1)Department of Prosthetics and Orthotics, College of Suncheon First, Suncheon,
Republic of Korea.

OBJECTIVE: To compare the muscle activity of the abductor hallucis (AbdH) and the
medial longitudinal arch (MLA) angle during toe curl (TC) and short foot (SF)
exercises while sitting or in one-leg standing position.
DESIGN: Two-way repeated-measures ANOVA was used to analyze the effects of
exercise type and position on the muscle activity of the AbdH and the MLA angle.
PARTICIPANTS: Twenty subjects with normal feet participated in this study.
MAIN OUTCOME MEASURES: The muscle activity of the AbdH and the MLA angle were
measured during TC and SF exercises while sitting or in one-leg standing
position.
RESULTS: The EMG activity of AbdH in SF exercise was significantly greater than
during TC exercise in both exercise postural positions (p < 0.001). During the SF
exercise, the EMG activity of the AbdH in the one-leg standing position was
significantly higher than that while sitting (p < 0.001). The MLA angle in SF
exercise was significantly smaller than during TC exercise in both postural
positions (p < 0.001).
CONCLUSIONS: These results suggest that SF exercise is a more useful
strengthening exercise than TC exercise in activating the AbdH muscle.

PMID: 21256447 [PubMed – indexed for MEDLINE]

J Biomech. 2011 Jan 4;44(1):116-20. doi: 10.1016/j.jbiomech.2010.08.034. Epub 2010 Sep 16.

Tissue vibration in prolonged running.

Friesenbichler B(1), Stirling LM, Federolf P, Nigg BM.

Author information:
(1)Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500
University Dr NW, Calgary, Alberta, Canada. berndf@kin.ucalgary.ca

The impact force in heel-toe running initiates vibrations of soft-tissue
compartments of the leg that are heavily dampened by muscle activity. This study
investigated if the damping and frequency of these soft-tissue vibrations are
affected by fatigue, which was categorized by the time into an exhaustive
exercise. The hypotheses were tested that (H1) the vibration intensity of the
triceps surae increases with increasing fatigue and (H2) the vibration frequency
of the triceps surae decreases with increasing fatigue. Tissue vibrations of the
triceps surae were measured with tri-axial accelerometers in 10 subjects during a
run towards exhaustion. The frequency content was quantified with power spectra
and wavelet analysis. Maxima of local vibration intensities were compared between
the non-fatigued and fatigued states of all subjects. In axial (i.e. parallel to
the tibia) and medio-lateral direction, most local maxima increased with fatigue
(supporting the first hypothesis). In anterior-posterior direction no systematic
changes were found. Vibration frequency was minimally affected by fatigue and
frequency changes did not occur systematically, which requires the rejection of
the second hypothesis. Relative to heel-strike, the maximum vibration intensity
occurred significantly later in the fatigued condition in all three directions.
With fatigue, the soft tissue of the triceps surae oscillated for an extended
duration at increased vibration magnitudes, possibly due to the effects of
fatigue on type II muscle fibers. Thus, the protective mechanism of muscle tuning
seems to be reduced in a fatigued muscle and the risk of potential harm to the
tissue may increase.

PMID: 20846656 [PubMed – indexed for MEDLINE]

Clin J Sport Med. 2010 Nov;20(6):428-35. doi: 10.1097/JSM.0b013e3181fb539f.

Comparative biomechanical effectiveness of over-the-counter devices for individuals with a flexible flatfoot secondary to forefoot varus.

Hurd WJ(1), Kavros SJ, Kaufman KR.

Author information:
(1)Department of Orthopedic Surgery, Motion Analysis Laboratory, Mayo Clinic,
Rochester, Minnesota, USA.

OBJECTIVES: Evaluate effects of a new off-the-shelf insert on frontal plane foot
biomechanics and compare effectiveness of the new and an existing off-the-shelf
insert and a motion-control shoe in neutralizing frontal plane foot biomechanics.
DESIGN: Descriptive.
SETTING: Biomechanics laboratory.
PARTICIPANTS: Fifteen uninjured subjects with a flexible flatfoot secondary to
forefoot varus.
ASSESSMENT OF RISK FACTORS: Three-dimensional kinematic and kinetic data were
collected as subjects walked and jogged at their self-selected speed while
wearing a motion-control running shoe, the shoe with a new off-the-shelf insert,
and the shoe with an existing off-the-shelf insert.
MAIN OUTCOME MEASURES: Frontal plane kinematics and rearfoot kinetics were
evaluated during stance. Statistical analysis was performed using a repeated
measures analysis of variance and Student-Newman-Keuls post hoc tests (α ≤ 0.05).
RESULTS: The new insert and motion-control shoe placed the forefoot in a
less-everted position than the existing off-the-shelf insert during walking.
There were no differences in forefoot kinematics during jogging, nor were there
differences in rearfoot motion during walking or jogging. The rearfoot eversion
moment was significantly lower with the new off-the-shelf insert compared with
the motion-control shoe and the existing insert during walking and jogging.
CONCLUSIONS: A new off-the-shelf device is available that promotes more neutral
frontal plane biomechanics, thus providing a theoretical rationale for using this
device for injury prevention and treatment. The comparative biomechanical
effectiveness of a motion-control shoe and the orthotic inserts may assist health
care professionals in selecting a device to correct the flatfoot structure.

PMID: 21079438 [PubMed – indexed for MEDLINE]

Foot Ankle Int. 2010 Nov;31(11):994-1000. doi: 10.3113/FAI.2010.0994.

Plantar pressure during running in subjects with chronic ankle instability.

Morrison KE(1), Hudson DJ, Davis IS, Richards JG, Royer TD, Dierks TA, Kaminski
TW.

Author information:
(1)West Chester University, Sports Medicine, 313 Sturzebecker Building, West Chester
University, West Chester, PA 19382, USA. kmorrison@wcupa.edu

BACKGROUND: It has been suggested that dynamic foot and ankle mechanics
predispose individuals with CAI to repetitive episodes of the ankle “giving
way.” Plantar pressure variations during a walking gait have been detected in
those with CAI, but more dynamic conditions for analysis are needed. The purpose
of this study was to evaluate plantar pressure distributions during a running
gait in individuals with CAI, individuals who suffered a lateral ankle sprain,
but did not develop CAI (AS), and subjects with no history of a lateral ankle
sprain (CON).
MATERIALS AND METHODS: Forty-five subjects [15 in each group, healthy males (18)
and females (27), age 18 to 45] were recruited from University communities to
participate in this study. Plantar pressure distributions were analyzed on a
Tekscan© plantar pressure mat at 66 frames per second during a running gait at a
controlled speed. The following variables were obtained: rearfoot medial/lateral
(M/L) pressure ratio at foot strike (FS) and center-of-pressure (COP) trajectory
during the initial loading response (heel strike to initial peak GRF). Separate
one-way ANOVA with Tukey’s post-hoc were used to test for group differences. The
significance level was defined as p < 0.05.
RESULTS: The CAI group had a significantly more lateral ratio (0.97 ± 0.12) at FS
when compared to the CON (1.01 ± 0.13) and AS (1.11 ± 0.13) groups. The CAI
subjects had a lateral COP trajectory during the loading phase (7.97 degrees ±
11.02), while both the AS (-3.68 degrees ± 10.24) and CON groups (-6.27 degrees ±
9.86) had medial trajectories. The difference was significant between the CAI
group and both the AS and CON groups (all significant {\it p} values were less
than 0.05).
CONCLUSION: Our results confirm that CAI subjects have a more lateral foot
positioning and loading pattern during a barefoot running gait when compared to
both the CON and LAS groups.
CLINICAL RELEVANCE: Clinicians treating patients with CAI should consider
providing interventions to decrease the amount of rearfoot inversion at FS and
during loading in order to create a more medial COP trajectory upon impact.

PMID: 21189193 [PubMed – indexed for MEDLINE]

J Am Podiatr Med Assoc. 2010 Nov-Dec;100(6):456-62.

Shoe preference based on subjective comfort for walking and running.

Kong PW(1), Bagdon M.

Author information:
(1)Department of Kinesiology, University of Texas at El Paso, TX, USA.
venikong@yahoo.com

BACKGROUND: Subjective comfort of footwear is important for shoe and orthosis
design. This study compared shoe preferences between walking and running, using
subjective comfort as an outcome tool.
METHODS: Forty-one participants walked and ran 20 times each along a runway in
three types of footwear (cushioning, lightweight, and stability) and chose the
model that they preferred most for walking and running separately based on
subjective comfort.
RESULTS: More participants preferred the cushioning model (walking, 34%; running,
41%) or the lightweight model (walking, 44%; running, 41%) over the stability
model (walking, 22%; running, 17%). χ² tests revealed no differences between
walking and running, runners and nonrunners, and lighter and heavier individuals.
Women were more likely (odds ratio = 4.09) to prefer the lightweight model,
whereas men preferred the cushioning (odds ratio = 2.05) and stability (odds
ratio = 3.19) models. Most participants (71%) chose the same model for both
activities.
CONCLUSIONS: Shoe preference varies among individuals and is influenced by sex.
Most people feel comfortable walking and running in the same shoe model.

PMID: 21084531 [PubMed – indexed for MEDLINE]

Am J Sports Med. 2010 Sep;38(9):1759-67. doi: 10.1177/0363546510369548. Epub 2010
Jun 24.

Injury reduction effectiveness of assigning running shoes based on plantar shape in Marine Corps basic training.

Knapik JJ(1), Trone DW, Swedler DI, Villasenor A, Bullock SH, Schmied E,
Bockelman T, Han P, Jones BH.

Author information:
(1)Directorate of Epidemiology and Disease Surveillance, US Army Public Health
Command, Aberdeen Proving Ground, MD 21010, USA. joseph.knapik@us.army.mil

Comment in
Clin J Sport Med. 2011 Sep;21(5):462-3.

BACKGROUND: Shoe manufacturers market motion control, stability, and cushioned
shoes for plantar shapes defined as low, normal, and high, respectively. This
assignment procedure is presumed to reduce injuries by compensating for
differences in running mechanics.
HYPOTHESIS: Assigning running shoes based on plantar shape will not reduce injury
risk in Marine Corps basic training.
STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1.
METHODS: After foot examinations, Marine Corps recruits in an experimental group
(E: 408 men, 314 women) were provided motion control, stability, or cushioned
shoes for plantar shapes indicative of low, medium, or high arches, respectively.
A control group (C: 432 men, 257 women) received a stability shoe regardless of
plantar shape. Injuries during the 12 weeks of training were determined from
outpatient visits obtained from the Defense Medical Surveillance System. Other
known injury risk factors (eg, fitness, smoking, prior physical activity) were
obtained from a questionnaire, existing databases, or the training units.
RESULTS: Cox regression indicated little difference in injury risk between the E
and C groups among men (hazard ratio [E/C] = 1.01; 95% confidence interval,
0.82-1.24) or women (hazard ratio [E/C] = 0.88; 95% confidence interval,
0.70-1.10).
CONCLUSION: This prospective study demonstrated that assigning shoes based on the
shape of the plantar foot surface had little influence on injuries even after
considering other injury risk factors.

PMID: 20576837 [PubMed – indexed for MEDLINE]

J Biomech. 2010 Aug 10;43(11):2120-5. doi: 10.1016/j.jbiomech.2010.04.001. Epub
2010 May 11.

Footwear affects the gearing at the ankle and knee joints during running.

Braunstein B(1), Arampatzis A, Eysel P, Brüggemann GP.

Author information:
(1)Institute of Biomechanics and Orthopaedics, German Sport University Cologne,
Germany. braunstein@dshs-koeln.de

The objective of the study was to investigate the adjustment of running mechanics
by wearing five different types of running shoes on tartan compared to barefoot
running on grass focusing on the gearing at the ankle and knee joints. The gear
ratio, defined as the ratio of the moment arm of the ground reaction force (GRF)
to the moment arm of the counteracting muscle tendon unit, is considered to be an
indicator of joint loading and mechanical efficiency. Lower extremity kinematics
and kinetics of 14 healthy volunteers were quantified three dimensionally and
compared between running in shoes on tartan and barefoot on grass. Results showed
no differences for the gear ratios and resultant joint moments for the ankle and
knee joints across the five different shoes, but showed that wearing running
shoes affects the gearing at the ankle and knee joints due to changes in the
moment arm of the GRF. During barefoot running the ankle joint showed a higher
gear ratio in early stance and a lower ratio in the late stance, while the gear
ratio at the knee joint was lower during midstance compared to shod running.
Because the moment arms of the counteracting muscle tendon units did not change,
the determinants of the gear ratios were the moment arms of the GRF’s. The
results imply higher mechanical stress in shod running for the knee joint
structures during midstance but also indicate an improved mechanical advantage in
force generation for the ankle extensors during the push-off phase.

PMID: 20462583 [PubMed – indexed for MEDLINE]

Foot (Edinb). 2010 Jun-Sep;20(2-3):64-70. doi: 10.1016/j.foot.2010.06.003. Epub
2010 Jul 24.

Rearfoot eversion has indirect effects on plantar fascia tension by changing the amount of arch collapse.

Lee SY(1), Hertel J, Lee SC.

Author information:
(1)University of Miami, United States. s.lee7@miami.edu

BACKGROUND: Rearfoot eversion motion and arch height are believed to contribute
to increased tension on the plantar fascia and arch collapse during gait but the
specifics of these relationships are not clear.
OBJECTIVE: To examine the relationships among static arch height, rearfoot
eversion, dynamic arch height, and plantar fascia tension.
METHODS: 28 healthy males participated. After static arch height was measured,
the subjects were asked to run at 4.5m/s while frontal plane rearfoot motion,
dynamic arch height, and ground reaction forces were collected. The relationships
among variables were examined with bivariate correlations and path analysis.
RESULTS: The results indicated a high correlation between dynamic arch height and
static arch height (r=0.642), plantar fascia tension (r=-0.797), and maximum
rearfoot eversion motion during gait (r=-0.518). The path analysis model without
the direct rearfoot eversion effect explained 81.2% of the variance in plantar
fascia tension, while the model with the direct rearfoot eversion effect
explained 82.1% of the variance in plantar fascia tension.
DISCUSSION: Including the indirect effect of maximum rearfoot eversion motion on
plantar fascia tension through control of dynamic arch height is the model that
best explains the interrelationships of these foot characteristics.
CONCLUSION: The amount of maximum rearfoot eversion motion itself is not a good
predictor of plantar fascia tension, however, together with the arch height,
maximum rearfoot eversion motion is a good predictor because it has a pronounced
indirect effect on plantar fascia tension.

PMID: 20656471 [PubMed – indexed for MEDLINE]

Foot Ankle Surg. 2010 Jun;16(2):70-3. doi: 10.1016/j.fas.2009.05.006. Epub 2009
Jul 9.

Repeatability of the Pedar-X in-shoe pressure measuring system.

Ramanathan AK(1), Kiran P, Arnold GP, Wang W, Abboud RJ.

Author information:
(1)Institute of Motion Analysis & Research, Department of Orthopaedic and Trauma
Surgery, TORT Centre, Ninewells Hospital & Medical School, University of Dundee,
Dundee DD1 9SY, UK.

Comment in
Z Orthop Unfall. 2010 Dec;148(6):631.

BACKGROUND: The Pedar-X is one of the newer versions of in-shoe pressure
measuring devices and the current study aimed to assess the repeatability of this
device.
METHODS: Twenty-seven healthy male volunteers were recruited and requested to
walk on a 26-feet walkway wearing appropriate sized standardised off-the-shelf
neutral running shoes (Donnay International). The Pedar-X insole was sandwiched
between the foot and the shoe. Data were collected on two occasions, one week
apart. Clinically relevant parameters studied were contact area, contact time in
percentage roll over process, maximum force, pressure-time integral, force-time
integral, peak pressure, mean force and mean area.
RESULTS: Repeatability was analysed using the coefficient of variation. Of the
160 parameters considered, 93.1% revealed a coefficient of variation value of
less than 25. Heel and the metatarsal head areas were the most repeatable.
CONCLUSION: The Pedar-X in-shoe pressure measuring system is repeatable and as
such can be used as a valuable tool in the assessment of in-shoe plantar pressure
distribution.

PMID: 20483137 [PubMed – indexed for MEDLINE]

Curr Sports Med Rep. 2010 May-Jun;9(3):176-82. doi: 10.1249/JSR.0b013e3181de7ec5.

Prevention of running injuries.

Fields KB(1), Sykes JC, Walker KM, Jackson JC.

Author information:
(1)Moses Cone Family Medicine Center, Greensboro, NC 27401, USA.
Bert.fields@mosescone.com

Evidence for preventive strategies to lessen running injuries is needed as these
occur in 40%-50% of runners on an annual basis. Many factors influence running
injuries, but strong evidence for prevention only exists for training
modification primarily by reducing weekly mileage. Two anatomical factors – cavus
feet and leg length inequality – demonstrate a link to injury. Weak evidence
suggests that orthotics may lessen risk of stress fracture, but no clear evidence
proves they will reduce the risk of those athletes with leg length inequality or
cavus feet. This article reviews other potential injury variables, including
strength, biomechanics, stretching, warm-up, nutrition, psychological factors,
and shoes. Additional research is needed to determine whether interventions to
address any of these will help prevent running injury.

PMID: 20463502 [PubMed – indexed for MEDLINE]

Gait Posture. 2010 May;32(1):133-5. doi: 10.1016/j.gaitpost.2010.01.015. Epub
2010 Apr 3.

Use of gait sandals for measuring rearfoot and shank motion during running.

Barnes A(1), Wheat J, Milner CE.

Author information:
(1)The Centre for Sport and Exercise Science, Sheffield Hallam University,
Collegiate Crescent Campus, Sheffield S10 2BP, UK. A.Barnes@shu.ac.uk

Gait sandals may be used as an alternative to shoes in gait analysis. However,
their similarity to running shoes remains unclear. This study aimed to compare
rearfoot and shank kinematics between barefoot, running shoes and gait sandal
conditions during running. We hypothesised that gait sandals would more closely
replicate the kinematics seen when wearing running shoes than when barefoot.
Rearfoot and shank kinematics were measured in 14 male participants as they ran
in three footwear conditions (barefoot, gait sandals and running shoes) at
3.5m/s. Both barefoot and gait sandals resulted in greater peak rearfoot eversion
compared to running shoes. Gait sandals were similar to running shoes for all
other variables. These findings suggest that gait sandals can be used in place of
running shoes during gait analysis to study rearfoot and shank kinematics.

PMID: 20363630 [PubMed – indexed for MEDLINE]

J Appl Biomech. 2010 May;26(2):205-14.

Effects of varying amounts of pronation on the mediolateral ground reaction forces during barefoot versus shod running.

Morley JB(1), Decker LM, Dierks T, Blanke D, French JA, Stergiou N.

Author information:
(1)Nebraska Biomechanics Core Facility, University of Nebraska at Omaha, Omaha, NE,
USA.

Despite extensive research on running mechanics, there is still a knowledge gap
with respect to the degree of relationship between mediolateral ground reaction
forces (ML-GRF) and foot pronation. Our goal was to investigate whether
differences exist in ML-GRF among runners that exhibit different degrees of
pronation. Seventeen male and 13 female recreational runners ran with and without
shoes while ML-GRF and frontal kinematics were collected simultaneously. Subjects
were divided into groups based upon their peak eversion (low pronation, middle
pronation, high pronation). Discrete parameters from the ML-GRF were peak forces,
respective times of occurrence, and impulses. No significant differences were
found between groups regarding the magnitude of ML-GRF. Based upon the relative
times of occurrence, the peak medial GRF occurred closer to the peak eversion
than the peak lateral GRF. Findings support the idea that the ML-GRF have less to
do with pronation than previous research suggested.

PMID: 20498492 [PubMed – indexed for MEDLINE]

Nature. 2010 Jan 28;463(7280):531-5. doi: 10.1038/nature08723.

Foot strike patterns and collision forces in habitually barefoot versus shod runners.

Lieberman DE(1), Venkadesan M, Werbel WA, Daoud AI, D’Andrea S, Davis IS,
Mang’eni RO, Pitsiladis Y.

Author information:
(1)Department of Human Evolutionary Biology, 11 Divinity Avenue, Harvard University,
Cambridge, Massachusetts 02138, USA. danlieb@fas.harvard.edu

Comment in
Nature. 2010 Jan 28;463(7280):433-4.

Humans have engaged in endurance running for millions of years, but the modern
running shoe was not invented until the 1970s. For most of human evolutionary
history, runners were either barefoot or wore minimal footwear such as sandals or
moccasins with smaller heels and little cushioning relative to modern running
shoes. We wondered how runners coped with the impact caused by the foot colliding
with the ground before the invention of the modern shoe. Here we show that
habitually barefoot endurance runners often land on the fore-foot (fore-foot
strike) before bringing down the heel, but they sometimes land with a flat foot
(mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast,
habitually shod runners mostly rear-foot strike, facilitated by the elevated and
cushioned heel of the modern running shoe. Kinematic and kinetic analyses show
that even on hard surfaces, barefoot runners who fore-foot strike generate
smaller collision forces than shod rear-foot strikers. This difference results
primarily from a more plantarflexed foot at landing and more ankle compliance
during impact, decreasing the effective mass of the body that collides with the
ground. Fore-foot- and mid-foot-strike gaits were probably more common when
humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs
from some of the impact-related injuries now experienced by a high percentage of
runners.

PMID: 20111000 [PubMed – indexed for MEDLINE]

Phys Ther. 2010 Jan;90(1):110-20. doi: 10.2522/ptj.20080298. Epub 2009 Nov 19.

Hallux valgus and the first metatarsal arch segment: a theoretical biomechanics perspective.

Glasoe WM(1), Nuckley DJ, Ludewig PM.

Author information:
(1)Program in Physical Therapy, University of Minnesota, Medical School, Mayo Mail
Code 388, 420 Delaware St SE, Minneapolis, MN 55455, USA. glaso008@umn.edu

Hallux valgus is a progressive foot deformity characterized by a lateral
deviation of the hallux with corresponding medial deviation of the first
metatarsal. Late-stage changes may render the hallux painful and without
functional utility, leading to impaired gait. Various environmental, genetic, and
anatomical predispositions have been suggested, but the exact cause of hallux
valgus is unknown. Evidence indicates that conservative intervention for hallux
valgus provides relief from symptoms but does not reverse deformity. Part 1 of
this perspective article reviews the literature describing the anatomy,
pathomechanics, and etiology of hallux valgus. Part 2 expands on the
biomechanical initiators of hallux valgus attributed to the first metatarsal.
Theory is advanced that collapse of the arch with vertical orientation (tilt) of
the first metatarsal axis initiates deformity. To counteract the progression of
hallux valgus, we use theory to discuss a possible mechanism by which foot
orthoses can bolster the arch and reorient the first metatarsal axis
horizontally.

PMID: 19926679 [PubMed – indexed for MEDLINE]

Med Sci Sports Exerc. 2009 Dec;41(12):2177-84. doi: 10.1249/MSS.0b013e3181a984c4.

Effects of stride length and running mileage on a probabilistic stress fracture model.

Edwards WB(1), Taylor D, Rudolphi TJ, Gillette JC, Derrick TR.

Author information:
(1)Department of Kinesiology, Iowa State University, Ames, IA 50011-1160, USA.
edwards9@iastate.edu

The fatigue life of bone is inversely related to strain magnitude. Decreasing
stride length is a potential mechanism of strain reduction during running. If
stride length is decreased, the number of loading cycles will increase for a
given mileage. It is unclear if increased loading cycles are detrimental to
skeletal health despite reductions in strain.PURPOSE: To determine the effects of
stride length and running mileage on the probability of tibial stress fracture.
METHODS: Ten male subjects ran overground at their preferred running velocity
during two conditions: preferred stride length and 10% reduction in preferred
stride length. Force platform and kinematic data were collected concurrently. A
combination of experimental and musculoskeletal modeling techniques was used to
determine joint contact forces acting on the distal tibia. Peak instantaneous
joint contact forces served as inputs to a finite element model to estimate
tibial strains during stance. Stress fracture probability for stride length
conditions and three running mileages (3, 5, and 7 miles x d(-1)) were determined
using a probabilistic model of bone damage, repair, and adaptation. Differences
in stress fracture probability were compared between conditions using a 2 x 3
repeated-measures ANOVA.
RESULTS: The main effects of stride length (P = 0.017) and running mileage (P =
0.001) were significant. Reducing stride length decreased the probability of
stress fracture by 3% to 6%. Increasing running mileage increased the probability
of stress fracture by 4% to 10%.
CONCLUSIONS: Results suggest that strain magnitude plays a more important role in
stress fracture development than the total number of loading cycles. Runners
wishing to decrease their probability for tibial stress fracture may benefit from
a 10% reduction in stride length.

PMID: 19915501 [PubMed – indexed for MEDLINE]

PM R. 2009 Dec;1(12):1058-63. doi: 10.1016/j.pmrj.2009.09.011.

The effect of running shoes on lower extremity joint torques.

Kerrigan DC(1), Franz JR, Keenan GS, Dicharry J, Della Croce U, Wilder RP.

Author information:
(1)JKM Technologies LLC, 525 Rookwood Place, Charlottesville, VA 22903, USA.
dckerrigan@oeshshoes.com

Comment in
PM R. 2010 Apr;2(4):310-1; author reply 311.

OBJECTIVE: To determine the effect of modern-day running shoes on lower extremity
joint torques during running.
DESIGN: Two-condition experimental comparison.
SETTING: A 3-dimensional motion analysis laboratory.
PARTICIPANTS: A total of 68 healthy young adult runners (37 women) who typically
run in running shoes.
METHODS: All subjects ran barefoot and in the same type of stability running
footwear at a controlled running speed. Three-dimensional motion capture data
were collected in synchrony with ground reaction force data from an instrumented
treadmill for each of the 2 conditions.
MAIN OUTCOME MEASUREMENTS: Peak 3-dimensional external joint torques at the hip,
knee, and ankle as calculated through a full inverse dynamic model.
RESULTS: Increased joint torques at the hip, knee, and ankle were observed with
running shoes compared with running barefoot. Disproportionately large increases
were observed in the hip internal rotation torque and in the knee flexion and
knee varus torques. An average 54% increase in the hip internal rotation torque,
a 36% increase in knee flexion torque, and a 38% increase in knee varus torque
were measured when running in running shoes compared with barefoot.
CONCLUSIONS: The findings at the knee suggest relatively greater pressures at
anatomical sites that are typically more prone to knee osteoarthritis, the medial
and patellofemoral compartments. It is important to note the limitations of these
findings and of current 3-dimensional gait analysis in general, that only
resultant joint torques were assessed. It is unknown to what extent actual joint
contact forces could be affected by compliance that a shoe might provide, a
potentially valuable design characteristic that may offset the observed increases
in joint torques.

PMID: 20006314 [PubMed – indexed for MEDLINE]

Br J Sports Med. 2009 Oct;43(10):745-9. doi: 10.1136/bjsm.2008.047761. Epub 2008 Sep 18.

Running in new and worn shoes: a comparison of three types of cushioning footwear.

Kong PW(1), Candelaria NG, Smith DR.

Author information:
(1)University of Texas at El Paso, El Paso, TX, USA. venikong@yahoo.com

OBJECTIVES: In this study, the effect of shoe degradation on running biomechanics
by comparing the kinetics and kinematics of running in new and worn shoes was
investigated. Three types of footwear using different cushioning technologies
were compared.
DESIGN: Longitudinal study.
SETTING: Pre- and post-tests on overground running at 4.5 m s(-1) on a 20-m
laboratory runway; performance measured using a force platform and a motion
capture system.
PARTICIPANTS: 24 runners (14 men and 10 women)
INTERVENTIONS: 200 miles of road running in the same pair of shoes. Within-group
factor: shoe condition (new/worn); between-group factor: footwear type
(air/gel/spring).
MAIN OUTCOME MEASUREMENTS: Stance time was calculated from force data. External
loads were measured by maximum vertical force and loading rate. Kinematic changes
were indicated by sagittal plane angles of the torso, hip, knee and ankle at
critical events during the stance phase.
RESULTS: Stance time increased (p=0.035) in worn shoes. The torso displayed less
maximum forward lean (p<0.001) and less forward lean at toe-off (p<0.001), while
the ankle displayed reduced maximum dorsiflexion (p=0.013) and increased plantar
flexion at toe-off (p<0.001) in worn shoes. No changes in the hip and knee
angles. No between-group difference among the three footwear groups or condition
by type interaction was found in any measured variables.
CONCLUSIONS: As shoe cushioning capability decreases, runners modify their
patterns to maintain constant external loads. The adaptation strategies to shoe
degradation were unaffected by different cushioning technologies, suggesting
runners should choose shoes for reasons other than cushioning technology.

PMID: 18801775 [PubMed – indexed for MEDLINE]

J Biomech. 2009 Sep 18;42(13):2081-8. doi: 10.1016/j.jbiomech.2009.06.015. Epub 2009 Jul 29.

The influence of footwear on foot motion during walking and running.

Morio C(1), Lake MJ, Gueguen N, Rao G, Baly L.

Author information:
(1)Oxylane Research, Department of Movement Sciences, 59665 Villeneuve d’Ascq Cedex,
France. cedric.morio@oxylane-group.com

There are evidences to suggest that wearing footwear constrains the natural
barefoot motion during locomotion. Unlike prior studies that deduced foot motions
from shoe sole displacement parameters, the aim of this study was to examine the
effect of footwear motion on forefoot to rearfoot relative motion during walking
and running. The use of a multi-segment foot model allowed accurate both shoe
sole and foot motions (barefoot and shod) to be quantified. Two pairs of
identical sandals with different midsole hardness were used. Ten healthy male
subjects walked and ran in each of the shod condition. The results showed that
for barefoot locomotion there was more eversion of the forefoot and it occurred
faster than for shod locomotion. In this later condition, the range of eversion
was reduced by 20% and the rate of eversion in late stance by 60% in comparison
to the barefoot condition. The sole constrained both the torsional
(eversion/inversion) and adduction range of motion of the foot. Interestingly,
during the push-off phase of barefoot locomotion the rate and direction of
forefoot torsion varied between individuals. However, most subjects displayed a
forefoot inversion direction of motion while shod. Therefore, this experiment
showed that the shoes not only restricted the natural motion of the barefoot but
also appeared to impose a specific foot motion pattern on individuals during the
push-off phase. These findings have implications for the matching of footwear
design characteristics to individual natural foot function.

PMID: 19643421 [PubMed – indexed for MEDLINE]

Comput Methods Biomech Biomed Engin. 2009 Aug;12(4):481-90. doi:
10.1080/10255840802695437.

Computer simulation of the effects of shoe cushioning on internal and external loading during running impacts.

Miller RH(1), Hamill J.

Author information:
(1)Department of Kinesiology, University of Massachusetts, Amherst, MA 01003, USA.
rhmiller@kin.umass.edu

Biomechanical aspects of running injuries are often inferred from external
loading measurements. However, previous research has suggested that relationships
between external loading and potential injury-inducing internal loads can be
complex and nonintuitive. Further, the loading response to training interventions
can vary widely between subjects. In this study, we use a subject-specific
computer simulation approach to estimate internal and external loading of the
distal tibia during the impact phase for two runners when running in shoes with
different midsole cushioning parameters. The results suggest that: (1) changes in
tibial loading induced by footwear are not reflected by changes in ground
reaction force (GRF) magnitudes; (2) the GRF loading rate is a better surrogate
measure of tibial loading and stress fracture risk than the GRF magnitude; and
(3) averaging results across groups may potentially mask differential responses
to training interventions between individuals.

PMID: 19225961 [PubMed – indexed for MEDLINE]

J Am Podiatr Med Assoc. 2009 Jul-Aug;99(4):330-8.

Effect of running shoe type on the distribution and magnitude of plantar
pressures in individuals with low- or high-arched feet.

Molloy JM(1), Christie DS, Teyhen DS, Yeykal NS, Tragord BS, Neal MS, Nelson ES,
McPoil T.

Author information:
(1)US Army-Baylor University Doctoral Program in Physical Therapy, Ft Sam Houston,
TX 78234-6138, USA. Joseph.Molloy@amedd.army.mil

BACKGROUND: Research addressing the effect of running shoe type on the low- or
high-arched foot during gait is limited. We sought 1) to analyze mean plantar
pressure and mean contact area differences between low- and high-arched feet
across three test conditions, 2) to determine which regions of the foot
(rearfoot, midfoot, and forefoot) contributed to potential differences in mean
plantar pressure and mean contact area, and 3) to determine the association
between the static arch height index and the dynamic modified arch index.
METHODS: Plantar pressure distributions for 75 participants (40 low arched and 35
high arched) were analyzed across three conditions (nonshod, motion control
running shoes, and cushioning running shoes) during treadmill walking.
RESULTS: In the motion control and cushioning shoe conditions, mean plantar
contact area increased in the midfoot (28% for low arched and 68% for high
arched), whereas mean plantar pressure decreased by approximately 30% relative to
the nonshod condition. There was moderate to good negative correlation between
the arch height index and the modified arch index.
CONCLUSIONS: Cushioning and motion control running shoes tend to increase midfoot
mean plantar contact area while decreasing mean plantar pressure across the low-
or high-arched foot.

PMID: 19605927 [PubMed – indexed for MEDLINE]

Int J Sports Med. 2009 May;30(5):379-82. doi: 10.1055/s-0028-1105932. Epub 2009

Feb 6.

Footwear and running cardio-respiratory responses.

Rubin DA(1), Butler RJ, Beckman B, Hackney AC.

Author information:
(1)Department of Kinesiology, California State University Fullerton, Fullerton
92834-3599, United States. drubin@fullerton.edu

This study compared cardio-respiratory responses during running wearing a motion
control shoe (MC) or a cushioning shoe (CU) in a cross-over single blinded
design. Fourteen runners (10F/4M, age=27.3+/-5.1 years, body mass=64.1+/-12.2 kg,
height=167.8+/-7.5 cm, VO (2)max=52.3+/-8.8 ml/kg/min) completed a 40-min run at
approximately 65% VO (2) max under both shoe conditions. Oxygen uptake
(mL/kg/min; L/min), minute ventilation (L/min), respiratory exchange ratio, and
heart rate were measured at minutes 8-10, 18-20, 28-30 and 38-40 of exercise.
Rating of perceived exertion was obtained at minutes 10, 20, 30 and 40. Two
(footwear) by four (time) repeated measures ANOVAs showed no differences between
footwear conditions in overall oxygen consumption (MC=36.8+/-1.5 vs.
CU=35.3+/-1.4 mL/kg/min, p=0.143), minute ventilation (MC=50.4+/-4 vs.
CU=48.5+/-3.8, p=0.147), respiratory exchange ratio (MC=0.90+/-0.01 vs.
CU=0.89+/-0.01, p=0.331), heart rate (MC=159+/-3 vs. CU=160+/-3, p=0.926), or
rate of perceived exertion. The design of motion control footwear does not appear
to affect cardio-respiratory or perceived exertion responses during submaximal
running. The findings are specific to the shoes tested. Nonetheless, the outcomes
suggest that footwear selection to reduce certain overuse injuries does not
increase the work of running.

PMID: 19199221 [PubMed – indexed for MEDLINE]

J Orthop Res. 2009 Mar;27(3):318-24. doi: 10.1002/jor.20744.

Shoes influence lower limb muscle activity and may predispose the wearer to lateral ankle ligament injury.

Kerr R(1), Arnold GP, Drew TS, Cochrane LA, Abboud RJ.

Author information:
(1)Institution of Motion Analysis & Research, Orthopaedic & Trauma Surgery, TORT
Centre, Ninewells Hospital & Medical School, University of Dundee, Dundee DD1
9SY, Scotland, United Kingdom.

Lateral ankle ligaments are injured by hyperinversion of the foot. Foot position
is controlled by the lower limb muscles. Awareness of foot position is impaired
by wearing shoes. We aimed to determine the influence of wearing shoes upon
muscle activity. Sixty-two healthy subjects underwent the same measurements,
barefoot and with standardized shoes in a random order. Electromyography (EMG)
was recorded from the peroneus longus muscle in response to sudden and
unanticipated inversion of the ipsilateral foot. Following foot inversion, the
EMG signal showed an initial peak muscle contraction followed by a sustained
smaller contraction. Both changes were significantly greater in shoes compared to
the barefoot condition for all tested degrees of inversion. Muscle contraction
following sudden inversion of the foot was significantly greater when wearing
shoes. This greater muscular contraction may be an intrinsic mechanism to oppose
the increased moment created by the inverted foot/shoe condition, and hence, may
counter balance the increased tendency to injure the lateral ankle ligaments
created by wearing shoes.

PMID: 18846547 [PubMed – indexed for MEDLINE]

J Sports Med Phys Fitness. 2009 Mar;49(1):6-13.

Biomechanical and physiological comparison of barefoot and two shod conditions in experienced barefoot runners.

Squadrone R(1), Gallozzi C.

Author information:
(1)Institute of Sport Medicine and Sport Science, Italian Olympic National
Committee, Rome, Italy.

AIM: The first aim of this study was to assess how changes in the mechanical
characteristics of the foot/shoe-ground interface affect spatio-temporal
variables, ground pressure distribution, sagittal plane kinematics, and running
economy in 8 experienced barefoot runners. The second aim was to assess if a
special lightweight shoe (Vibram Fivefingers) was effective in mimic the
experience of barefoot running.
METHODS: By using an instrumented treadmill, barefoot running, running with the
Fivefingers, and running with standard running shoe were compared, analyzing a
large numbers of consecutive steps. Foot/shoe-ground interface pressure
distribution, lower limb kinematics, V.O(2) and heart rate data were
simultaneously collected.
RESULTS: Compared to the standard shod condition when running barefoot the
athletes landed in more plantarflexion at the ankle. This caused reduced impact
forces and changes in stride kinematics. In particular, significantly shorter
stride length and contact times and higher stride frequency were observed
(P<0.05). Compared to standard shod condition, V.O(2) and peak impact forces were
significantly lower with Fivefingers (P<0.05) and much closer to barefoot
running. Lower limb kinematics with Fivefingers was similar to barefoot running
with a foot position which was significantly more plantarflexed than in control
shoe (P<0.05).
CONCLUSIONS: The data of this study support the assumption that changes in the
foot-ground interface led to changes in running pattern in a group of experienced
barefoot runners. The Fivefingers model seems to be effective in imitating the
barefoot conditions while providing a small amount of protection.

PMID: 19188889 [PubMed – indexed for MEDLINE]

Scand J Med Sci Sports. 2008 Dec;18(6):691-7. doi:
10.1111/j.1600-0838.2007.00768.x. Epub 2008 Feb 4.

Risk factors for lower extremity injuries among male marathon runners.

Van Middelkoop M(1), Kolkman J, Van Ochten J, Bierma-Zeinstra SM, Koes BW.

Author information:
(1)Department of General Practice, Erasmus MC, CA Rotterdam, The Netherlands.
m.vanmiddelkoop@erasmusmc.nl

Comment in
Scand J Med Sci Sports. 2008 Dec;18(6):677-8.

The aim of this study is to identify risk factors for lower extremity injuries in
male marathon runners. A random sample of 1500 recreational male marathon runners
was drawn. Possible risk factors were obtained from a baseline questionnaire 1
month before the start of the marathon. Information on injuries sustained shortly
before or during the marathon was obtained using a post-race questionnaire. Of
the 694 male runners who responded to the baseline and post-race questionnaire,
28% suffered a self-reported running injury on the lower extremities in the month
before or during the marathon run. More than six times race participation in the
previous 12 months [odds ratio (OR) 1.66; confidence interval (CI) 1.08-2.56], a
history of running injuries (OR 2.62; CI 1.82-3.78), high education level (OR
0.73; CI 0.51-1.04) and daily smoking (OR 0.23; CI 0.05-1.01) were associated
with the occurrence of lower extremity injuries. Among the modifiable risk factor
studies, a training distance <40 km a week is a strong protective factor of
future calf injuries, and regular interval training is a strong protective factor
for knee injuries. Other training characteristics appear to have little or no
effect on future injuries.

PMID: 18266787 [PubMed – indexed for MEDLINE]

Am J Sports Med. 2008 Nov;36(11):2139-46. doi: 10.1177/0363546508318191. Epub

2008 Jun 24.

Effect of neutral-cushioned running shoes on plantar pressure loading and comfort in athletes with cavus feet: a crossover randomized controlled trial.

Wegener C(1), Burns J, Penkala S.

Author information:
(1)Podiatry Program, School of Biomedical and Health Sciences, University of Western
Sydney, Sydney, NSW, Australia. Caleb.Wegener@swahs.health.nsw.gov.au

BACKGROUND: High injury rates observed in athletes with cavus feet are thought to
be associated with elevated plantar pressure loading. Neutral-cushioned running
shoes are often recommended to manage and prevent such injuries.
PURPOSE: To investigate in-shoe plantar pressure loading and comfort during
running in 2 popular neutral-cushioned running shoes recommended for athletes
with cavus feet.
STUDY DESIGN: Controlled laboratory study.
METHODS: Plantar pressures were collected using the in-shoe Novel Pedar-X system
during overground running in 22 athletes with cavus feet in 2 neutral-cushioned
running shoes (Asics Nimbus 6 and Brooks Glycerin 3) and a control condition
(Dunlop Volley). Comfort was measured using a validated visual analog scale.
RESULTS: Compared with the control, both neutral-cushioned running shoes
significantly reduced peak pressure and pressure-time integrals by 17% to 33% (P
< .001). The Brooks Glycerin most effectively reduced pressure beneath the whole
foot and forefoot (P < .01), and the Asics Nimbus most effectively reduced
rearfoot pressure (P <.01). Both neutral-cushioned running shoes reduced force at
the forefoot by 6% and increased it at the midfoot by 12% to 17% (P < .05).
Contact time and area increased in both neutral-cushioned running shoes (P <
.01). The Asics Nimbus was the most comfortable, although both neutral-cushioned
running shoes were significantly more comfortable than the control (P < .001).
CONCLUSION: Two popular types of neutral-cushioned running shoes were effective
at reducing plantar pressures in athletes with cavus feet.
CLINICAL RELEVANCE: Regional differences in pressure reduction suggest
neutral-cushioned running shoe recommendation should shift from being categorical
in nature to being based on location of injury or elevated plantar pressure.

PMID: 18577583 [PubMed – indexed for MEDLINE]

Clin J Sport Med. 2008 Jul;18(4):338-43. doi: 10.1097/MJT.0b013e31815fa75a.

Short- and long-term influences of a custom foot orthotic intervention on lower extremity dynamics.

MacLean CL(1), Davis IS, Hamill J.

Author information:
(1)Biomechanics Laboratory, Department of Kinesiology, University of
Massachusetts-Amherst, Amherst, Massachusetts, USA. cmaclean@parisorthotics.com

OBJECTIVE: The objective of the current study was to analyze the influence of a
short-term and long-term custom foot orthotic (CFO) intervention on the lower
extremity dynamics in a group of female runners with a history of overuse running
knee injury.
DESIGN: Descriptive laboratory study.
SETTING: University of Massachusetts Biomechanics Laboratory, Amherst, MA.
PARTICIPANTS: This study included a group of female recreational runners (15 to
40 km per week) who had a history of overuse running knee injury in the 6 months
leading up to the study.
INTERVENTION: Semi-rigid, custom foot orthoses manufactured from a neutral
suspension cast and designed to meet the specific needs of each subject. Subjects
wore the custom foot orthoses during all running activities for a period of 6
weeks.
MAIN OUTCOME MEASURES: Three-dimensional ankle and knee dynamics were collected
while subjects performed over-ground running trials with and without a CFO
intervention. Data were collected before and after a 6-week CFO intervention
during all running activities.
RESULTS: For ankle parameters, short-term intervention led to significant
decreases in maximum values for rearfoot eversion angle and velocity, impact
peak, and loading rate. Ankle inversion impulse was also significantly decreased
during the loading phase. At the knee, maximum knee external rotation moment was
significantly increased when subjects wore the custom foot orthoses.
CONCLUSIONS: The 6-week intervention led to subjective changes, including a
significant decrease in pain. An improvement in symptoms did occur with the
6-week intervention. In addition, dynamic results revealed that custom foot
orthoses have an immediate effect on dynamics and that this influence occurs only
when orthoses are worn in the footwear. The short-term CFO intervention led to
significant decreases in rearfoot kinematics (maximum eversion angle and
velocity) but no changes observed in knee kinematics. The kinetic analysis
revealed that these subjects exhibited significant decreases in maxima for ankle
inversion moment and angular impulse during the loading phase, impact peak, and
vertical loading rate with short-term, CFO intervention. At the knee, the CFO
condition led to increases in knee external rotation moment maxima and angular
impulse.

PMID: 18614885 [PubMed – indexed for MEDLINE]

Foot Ankle Int. 2008 Jul;29(7):671-6.

Acute and overuse injuries correlated to hours of training in master running athletes.

Knobloch K(1), Yoon U, Vogt PM.

Author information:
(1)Hannover Medical School, Plastic, Hand and Reconstructive Surgery,
Carl-Neuberg-Str. I, Hannover 30625, Germany. kknobi@yahoo.com

BACKGROUND: The goal of the study was to determine the rate of running-associated
tendinopathy in light of the amount of time training and other risk factors.
MATERIALS AND METHODS: 291 elite runners (average age 42 +/- 9 years) who ran an
average of 65.2 +/- 28.3 km/week were included with an overall distance of
9,980,852 km (34,416 km/athlete). Descriptive statistics with Chi2-Test,
Fisher-Exact-Test and Mann-Whitney-Test were used to calculate relative risks
(RR).
RESULTS: The overall injury rate was 0.08/1000 km (2.93/athlete). Overuse
injuries (0.07/1000 km) were more frequent than acute injuries (0.01/1000 km).
Achilles tendinopathy was the predominant injury (0.02/1000 km) followed by
anterior knee pain (0.01/1000 km), and shin splints (0.01/1000 km). Achilles
tendon rupture was rarely encountered (0.001/1000 km). At some time, 56.6% of the
athletes had an Achilles tendon overuse injury, 46.4% anterior knee pain, 35.7%
shin splints, and 12.7% had plantar fasciitis. Mid-portion Achilles tendinopathy
was more common (0.01/1000 km) than insertional (0.005/1000 km). An asphalt
running surface decreased mid-portion tendinopathy risk (RR 0.47, p = 0.02). In
contrast, sand increased the relative risk for mid-portion Achilles tendinopathy
tenfold (RR 10, CI 1.12 to 92.8, p = 0.01). Runners with more than 10 years
experience had an increased risk (RR 1.6, p = 0.04) for Achilles tendinopathy.
CONCLUSION: Achilles tendinopathy is the most common running-associated
tendinopathy followed by runner’s knee and shin splints.

PMID: 18785416 [PubMed – indexed for MEDLINE]

Int J Sports Med. 2008 Jun;29(6):512-8. Epub 2007 Nov 16.

Barefoot-shod running differences: shoe or mass effect?

Divert C(1), Mornieux G, Freychat P, Baly L, Mayer F, Belli A.

Author information:
(1)LAMIH, Université de Valenciennes, Valenciennes, France.
caroline.divert@univ-valenciennes.fr

Comment in
Int J Sports Med. 2012 Mar;33(3):249; author reply 250.

The higher oxygen consumption reported when shod running is compared to barefoot
running has been attributed to the additional mass of the shoe. However, it has
been reported that wearing shoes also modified the running pattern. The aim of
this study was to distinguish the mass and shoe effects on the mechanics and
energetics when shod running. Twelve trained subjects ran on a 3-D treadmill
ergometer at 3.61 m . s (-1) in six conditions: barefoot, using ultra thin diving
socks unloaded, loaded with 150 g, loaded with 350 g, and two shoe conditions,
one weighing 150 g and another 350 g. The results show that there was a
significant mass effect but no shoe effect for oxygen consumption. Stride
frequency, anterior-posterior impulse, vertical stiffness, leg stiffness, and
mechanical work were significantly higher in barefoot condition compared to shod.
Net efficiency, which has metabolic and mechanical components, decreased in the
shod condition. The mechanical modifications of running showed that the main role
of the shoe was to attenuate the foot-ground impact by adding damping material.
However, these changes may lead to a decrease of the storage and restitution of
elastic energy capacity which could explain the lower net efficiency reported in
shod running.

PMID: 18027308 [PubMed – indexed for MEDLINE]

Br J Sports Med. 2008 Mar;42(3):189-93. Epub 2007 Oct 11.

Do you get value for money when you buy an expensive pair of running shoes?

Clinghan R(1), Arnold GP, Drew TS, Cochrane LA, Abboud RJ.

Author information:
(1)Institute of Motion Analysis and Research, TORT Centre, Ninewells Hospital and
Medical School, University of Dundee, Dundee, UK.

OBJECTIVE: This investigation aims to determine if more expensive running shoes
provide better cushioning of plantar pressure and are more comfortable than
low-cost alternatives from the same brand.
METHODS: Three pairs of running shoes were purchased from three different
manufacturers at three different price ranges: low (40-45 pounds), medium (60-65
pounds) and high (70-75 pounds). Plantar pressure was recorded with the Pedar
in-shoe pressure measurement system. Comfort was assessed with a 100 mm visual
analogue scale. A follow-on study was conducted to ascertain if shoe cushioning
and comfort were comparable to walking while running on a treadmill. Forty-three
and 9 male subjects participated in the main and follow-on studies, respectively.
The main outcome measure was the evaluation of plantar pressure and comfort.
RESULTS: Plantar pressure measurements were recorded from under the heel, across
the forefoot and under the great toe. Differences in plantar pressure were
recorded between models and between brands in relation to cost. Shoe performance
was comparable between walking and running trials on a treadmill. No significant
difference was observed between shoes and test occasions in terms of comfort.
CONCLUSIONS: Low- and medium-cost running shoes in each of the three brands
tested provided the same (if not better) cushioning of plantar pressure as
high-cost running shoes. Cushioning was comparable when walking and running on a
treadmill. Comfort is a subjective sensation based on individual preferences and
was not related to either the distribution of plantar pressure or cost.

PMID: 17932096 [PubMed – indexed for MEDLINE]

Gait Posture. 2008 Jan;27(1):51-9. Epub 2007 Mar 13.

Foot motion in children shoes: a comparison of barefoot walking with shod walking in conventional and flexible shoes.

Wolf S(1), Simon J, Patikas D, Schuster W, Armbrust P, Döderlein L.

Author information:
(1)Department of Orthopedic Surgery, University of Heidelberg, Schlierbacher
Landstrasse 200a, 69118, Heidelberg, Germany. Sebastian.Wolf@ok.uni-hd.de

The increased prevalence for flatfoot and hallux valgus in modern societies may
be the consequence of inadequate footwear in childhood. Based on the assumption
that barefoot walking represents the best condition for the development of a
healthy foot the objective of this study was to monitor the influence of
commercial footwear on children’s foot motion during walking. Furthermore, an
attempt was made to reduce this influence by changing the physical properties of
standard footwear. Children’s barefoot motion pattern was monitored by a
marker-based optical 3D-tracking method using a multi-segment foot model. In the
study’s first stage, barefoot walking was compared to walking with a commercial
product. In the second stage it was compared to both, the pattern with the
commercial product and with the shoe modified on the basis of the findings of the
first stage of the study. Eighteen children (8.2+/-0.7 years old) with no foot
deformity and with the same shoe size were recruited for this study. It was found
that tibio-talar ROM increased in the commercial shoe (26.6 degrees ) compared to
the barefoot condition (22.5 degrees , p=0.001) whereas the medial arch changes
for push-off were diminished since the variation in arch length was reduced from
9.9% (barefoot) to 5.9% (shoe, p<0.001). Further, ROM in foot torsion along the
long foot axis was reduced from 9.8 degrees (bare) to 4.7 degrees (shoe,
p<0.001). These parameters could be improved with more flexible footwear. The
present study shows that slimmer and more flexible children’s shoes do not change
foot motion as much as conventional shoes and therefore should be recommended not
only for children in this age but for healthy children in general.

PMID: 17353125 [PubMed – indexed for MEDLINE]

Gait Posture. 2008 Jan;27(1):152-5. Epub 2007 Feb 5.

Long distance running increases plantar pressures beneath the metatarsal heads: a barefoot walking investigation of 200 marathon runners.

Nagel A(1), Fernholz F, Kibele C, Rosenbaum D.

Author information:
(1)Movement Analysis Lab., Orthopaedic Department, University Hospital of Muenster,
Domagkstr 3, 48149, Muenster, Germany. anagel@uni-muenster.de

BACKGROUND: The growing popularity of endurance sports activities is associated
with a growing number of metatarsal stress fractures in recreational runners.
Excessive foot loading has been suggested as a potential cause for these problems
[Bennell, K, Matheson G, Meeuwisse W, Brukner P. Risk factors for stress
fractures. Sports Med 1999;28(2):91-122]. Therefore, the question arises whether
long distance running affects foot loading characteristics like ground reaction
forces and peak pressure in specific areas of the foot.
PURPOSE: To investigate the effects of long distance running on plantar pressure
patterns before and after a marathon race.
STUDY DESIGN: Repeated measurements of recreational runners before and after a
marathon race.
METHODS: Two hundred participants of the third Muenster marathon, 2004, were
measured before and after the race with plantar pressure measurements during
barefoot walking on a capacitive platform. The ratio between forefoot and toe
loading was calculated to assess a suggested loading shift between these areas.
RESULTS: The results of the whole group of participants revealed a significant
difference in foot loading characteristics before and after the race. Post-race
peak pressure and impulse values were higher in the forefoot regions and reduced
under the toes.
CONCLUSIONS: The increased peak pressure under the metatarsal heads after the
race indicates a load shift from the toes to the metatarsal heads. This suggests
an increased loading of the metatarsal bones and could explain the increased
incidence of metatarsal stress fractures in long distance runners.

PMID: 17276688 [PubMed – indexed for MEDLINE]

J Am Podiatr Med Assoc. 2008 Jan-Feb;98(1):36-41.

Effect of cushioned insoles on impact forces during running.

O’Leary K(1), Vorpahl KA, Heiderscheit B.

Author information:
(1)Sports Rehabilitation Clinic, University of Wisconsin Hospital and Clinics,
Madison, USA.

BACKGROUND: The use of cushioned or shock-absorbing insoles has been suggested as
a mechanism to reduce the impact forces associated with running, thereby
protecting against overuse injuries. The purpose of this study was to determine
whether the use of cushioned insoles reduced impact forces during running in
healthy subjects.
METHODS: Sixteen recreational runners (9 females and 7 males) ran at a
self-selected pace for five trials with and without the use of cushioned insoles.
During each trial, ground reaction forces, tibial accelerations, lower-extremity
kinematics, and subject-perceived comfort were recorded. All variables were
tested with the level of statistical significance set at alpha = .05.
RESULTS: The use of cushioned insoles resulted in significant reductions in mean
vertical ground reaction force peak impact (6.8%) and ground reaction force
loading rate (8.3%), as well as peak tibial acceleration (15.8%). Spectral
analysis of the tibial acceleration data in the frequency range associated with
impact accelerations (12-25 Hz) revealed no change in the predominant frequency
or the power of the predominant frequency. The knee flexion angle at initial
contact and perceived comfort were similar for the two conditions.
CONCLUSIONS: This study demonstrates the effectiveness of one type of cushioned
insole in reducing peak impact force and tibial acceleration at initial
foot-ground contact during running. The impact reduction observed was independent
of knee kinematic adjustments or changes in perceived comfort. Further study is
required to determine whether the reduction in loading that accompanied the use
of the cushioned insoles can affect the incidence of running-related injuries.

PMID: 18202332 [PubMed – indexed for MEDLINE]

Br J Sports Med. 2007 Aug;41(8):469-80; discussion 480. Epub 2007 May 1.

Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review.

van Gent RN(1), Siem D, van Middelkoop M, van Os AG, Bierma-Zeinstra SM, Koes BW.

Author information:
(1)Erasmus MC Rotterdam, Rotterdam, Netherlands.

Comment in
Clin J Sport Med. 2009 Jan;19(1):77.

The purpose of this study was to present a systematic overview of published
reports on the incidence and associated potential risk factors of lower extremity
running injuries in long distance runners. An electronic database search was
conducted using the PubMed-Medline database. Two observers independently assessed
the quality of the studies and a best evidence synthesis was used to summarise
the results. The incidence of lower extremity running injuries ranged from 19.4%
to 79.3%. The predominant site of these injuries was the knee. There was strong
evidence that a long training distance per week in male runners and a history of
previous injuries were risk factors for injuries, and that an increase in
training distance per week was a protective factor for knee injuries.

PMCID: PMC2465455
PMID: 17473005 [PubMed – indexed for MEDLINE]

J Strength Cond Res. 2007 Aug;21(3):888-93.

Foot strike patterns of runners at the 15-km point during an elite-level half marathon.

Hasegawa H(1), Yamauchi T, Kraemer WJ.

Author information:
(1)Laboratory of Exercise Science, Department of Business Management, Ryukoku
University, Kyoto, Japan. hiroshi515@aol.com

There are various recommendations by many coaches regarding foot landing
techniques in distance running that are meant to improve running performance and
prevent injuries. Several studies have investigated the kinematic and kinetic
differences between rearfoot strike (RFS), midfoot strike (MFS), and forefoot
strike (FFS) patterns at foot landing and their effects on running efficiency on
a treadmill and over ground conditions. However, little is known about the actual
condition of the foot strike pattern during an actual road race at the elite
level of competition. The purpose of the present study was to document actual
foot strike patterns during a half marathon in which elite international level
runners, including Olympians, compete. Four hundred fifteen runners were filmed
by 2 120-Hz video cameras in the height of 0.15 m placed at the 15.0-km point and
obtained sagittal foot landing and taking off images for 283 runners. Rearfoot
strike was observed in 74.9% of all analyzed runners, MFS in 23.7%, and FFS in
1.4%. The percentage of MFS was higher in the faster runners group, when all
runners were ranked and divided into 50 runner groups at the 15.0-km point of the
competition. In the top 50, which included up to the 69th place runner in actual
order who passed the 15-km point at 45 minutes, 53 second (this speed represents
5.45 m x s(-1), or 15 minutes, 17 seconds per 5 km), RFS, MFS, and FFS were 62.0,
36.0, and 2.0%, respectively. Contact time (CT) clearly increased for the slower
runners, or the placement order increased (r = 0.71, p < or = 0.05). The CT for
RFS + FFS for every 50 runners group significantly increased with increase of the
placement order. The CT for RFS was significantly longer than MFS + FFS (200.0
+/- 21.3 vs. 183.0 +/- 16 millisecond). Apparent inversion (INV) of the foot at
the foot strike was observed in 42% of all runners. The percentage of INV for MFS
was higher than for RFS and FFS (62.5, 32.0, and 50%, respectively). The CT with
INV for MFS + FFS was significantly shorter than the CT with and without INV for
RFS. Furthermore, the CT with INV was significantly shorter than push-off time
without INV for RFS. The findings of this study indicate that foot strike
patterns are related to running speed. The percentage of RFS increases with the
decreasing of the running speed; conversely, the percentage of MFS increases as
the running speed increases. A shorter contact time and a higher frequency of
inversion at the foot contact might contribute to higher running economy.

PMID: 17685722 [PubMed – indexed for MEDLINE]

Gait Posture. 2007 Jul;26(2):219-25. Epub 2006 Oct 20.

Effect of footwear on high and low arched runners’ mechanics during a prolonged run.

Butler RJ(1), Hamill J, Davis I.

Author information:
(1)Department of Physical Therapy, University of Evansville, 1800 Lincoln Avenue,
Evansille, IN 47722, USA. rb83@evansville.edu

INTRODUCTION: Running shoes are designed specifically for different foot types in
order to reduce injuries. Running in the correct footwear matched for foot type
may have a greater influence on mechanics when runners become exerted. Therefore,
the purpose of this study was to evaluate changes in kinematics and kinetics over
the course of a prolonged run when low (LA) and high (HA) arched runners wear
motion control and cushioning shoes.
METHODS: Twelve HA and 12 LA recreational runners were recruited for this study.
Subjects ran in a motion control (MC) and cushion trainer (CT) shoe. Lower
extremity kinematics and tibial accelerometry were collected while the runners
ran at a self-selected training pace. The data were analyzed using a two-way
(footwear x time) repeated measures ANOVA (p=0.05) for each arch type.
RESULTS: Low arched runners: Peak tibial internal rotation decreased in the MC
shoe and was increased in the CT over the course of the prolonged run. However,
no interactions or main effects were noted for peak eversion or eversion
excursion. High arched runners: No shoe by time interaction was observed for
tibial shock. However, there was a main effect for shoe, with lower tibial shock
associated with the CT shoe.
CONCLUSION: In LA runners, MC shoes decreased tibial internal rotation compared
to CT shoes over the course of a prolonged run. In HA runners, running in the CT
shoes reduced tibial shock compared to the MC shoes.

PMID: 17055729 [PubMed – indexed for MEDLINE]

Clin Biomech (Bristol, Avon). 2007 Jan;22(1):74-80. Epub 2006 Oct 17.

Forefoot-rearfoot coupling patterns and tibial internal rotation during stance phase of barefoot versus shod running.

Eslami M(1), Begon M, Farahpour N, Allard P.

Author information:
(1)Department of Kinesiology, University of Montreal, Montreal, Quebec, Canada.
mansour.eslami@umontreal.ca

BACKGROUND: Based on twisted plate and mitered hinge models of the foot and
ankle, forefoot-rearfoot coupling motion patterns can contribute to the amount of
tibial rotation. The present study determined the differences of
forefoot-rearfoot coupling patterns as well as excessive excursion of tibial
internal rotation in shod versus barefoot conditions during running.
METHODS: Sixteen male subjects ran 10 times at 170 steps per minute under the
barefoot and shod conditions. Forefoot-rearfoot coupling motions were assessed by
measuring mean relative phase angle during five intervals of stance phase for the
main effect of five time intervals and two conditions (ANOVA, P<0.05). Tibial
internal rotation excursion was compared between the shod and barefoot conditions
over the first 50% of stance phase using paired t-test, (P<0.05).
FINDINGS: Forefoot adduction/abduction and rearfoot eversion/inversion coupling
motion patterns were significantly different between the conditions and among the
intervals (P<0.05; effect size=0.47). The mean absolute relative angle was
significantly modified to 37 degrees in-phase relationship at the heel-strike of
running with shoe wears. No significant differences were noted in the tibial
internal rotation excursion between shod and barefoot conditions.
INTERPRETATION: Significant variations in the forefoot adduction/abduction and
rearfoot eversion/inversion coupling patterns could have little effect on the
amount of tibial internal rotation excursion. Yet it remains to be determined
whether changes in the frontal plane forefoot-rearfoot coupling patterns
influence the tibia kinematics for different shoe wears or foot orthotic
interventions. The findings question the rational for the prophylactic use of
forefoot posting in foot orthoses.

PMID: 17049700 [PubMed – indexed for MEDLINE]

Am J Sports Med. 2006 Dec;34(12):1998-2005. Epub 2006 Aug 10.

Interaction of arch type and footwear on running mechanics.

Butler RJ(1), Davis IS, Hamill J.

Author information:
(1)Department of Exercise and Sport Science, University of North Carolina at Chapel
Hill, Chapel Hill, North Carolina, USA. robertjbutler@lycos.com

BACKGROUND: Running shoes are designed to accommodate various arch types to
reduce the risk of lower extremity injuries sustained during running. Yet little
is known about the biomechanical changes of running in the recommended footwear
that may allow for a reduction in injuries.
PURPOSE: To evaluate the effects of motion control and cushion trainer shoes on
running mechanics in low- and high-arched runners.
STUDY DESIGN: Controlled laboratory study.
METHODS: Twenty high-arched and 20 low-arched recreational runners (>10 miles per
week) were recruited for the study. Three-dimensional kinematic and kinetics were
collected as subjects ran at 3.5 ms(-1) +/- 5% along a 25-m runway. The motion
control shoe evaluated was the New Balance 1122, and the cushioning shoe
evaluated was the New Balance 1022. Repeated-measures analyses of variance were
used to determine if low- and high-arched runners responded differently to motion
control and cushion trainer shoes.
RESULTS: A significant interaction was observed in the instantaneous loading rate
such that the low-arched runners had a lower instantaneous loading rate in the
motion control condition, and the high-arched runners had a lower instantaneous
loading rate in the cushion trainer condition. Significant main effects for shoe
were observed for peak positive tibial acceleration, peak-to-peak tibial
acceleration, mean loading rate, peak eversion, and eversion excursion.
CONCLUSION: These results suggest that motion control shoes control rearfoot
motion better than do cushion trainer shoes. In addition, cushion trainer shoes
attenuate shock better than motion control shoes do. However, with the exception
of instantaneous loading rate, these benefits do not differ between arch type.
CLINICAL RELEVANCE: Running footwear recommendations should be based on an
individual’s running mechanics. If a mechanical analysis is not available,
footwear recommendations can be based empirically on the individual’s arch type.

PMID: 16902231 [PubMed – indexed for MEDLINE]

J Athl Train. 2006 Oct-Dec;41(4):387-92.

Athletic footwear, leg stiffness, and running kinematics.

Bishop M(1), Fiolkowski P, Conrad B, Brunt D, Horodyski M.

Author information:
(1)University of Florida, Gainesville, FL, USA. mbishop@phhp.ufl.edu

CONTEXT: The leg acts as a linear spring during running and hopping and adapts to
the stiffness of the surface, maintaining constant total stiffness of the
leg-surface system. Introducing a substance (eg, footwear) may affect the
stiffness of the leg in response to changes in surface stiffness.
OBJECTIVE: To determine if the type of athletic footwear affects the regulation
of leg stiffness in dynamic activities.
DESIGN: Repeated-measures design.
SETTING: Motion analysis laboratory.
PATIENTS OR OTHER PARTICIPANTS: Nine healthy adults (age = 28 +/- 6.8 years, mass
= 71.6 +/- 12.9 kg) free from lower extremity injuries.
INTERVENTION(S): Subjects hopped at 2.2 Hz on a forceplate under 3 footwear
conditions (barefoot, low-cost footwear, high-cost footwear). Subjects ran on a
treadmill at 2 speeds (2.23 m/s, 3.58 m/s) under the same footwear conditions.
MAIN OUTCOME MEASURE(S): Limb stiffness was calculated from forceplate data.
Kinematic data (knee and ankle angles at initial contact and peak joint excursion
after contact) were collected during running. We calculated 1-way
repeated-measures (stiffness) and 2-way (speed by footwear) repeated-measures
analyses of variance (running kinematics) to test the dependent variables.
RESULTS: A significant increase in leg stiffness from the barefoot to the
“cushioned” shoe condition was noted during hopping. When running shod, runners
landed in more dorsiflexion but had less ankle motion than when running barefoot.
No differences were seen between the types of shoes. The primary kinematic
difference was identified as running speed increased: runners landed in more knee
flexion. At the ankle, barefoot runners increased ankle motion to a significantly
greater extent than did shod runners as speed increased.
CONCLUSIONS: Footwear influences the maintenance of stiffness in the lower
extremity during hopping and joint excursion at the ankle in running. Differences
in cushioning properties of the shoes tested did not appear to be significant.

PMCID: PMC1748411
PMID: 17273463 [PubMed]

Clin Biomech (Bristol, Avon). 2006 Jul;21(6):623-30. Epub 2006 Apr 5.

Influence of a custom foot orthotic intervention on lower extremity dynamics in healthy runners.

MacLean C(1), Davis IM, Hamill J.

Author information:
(1)Department of Exercise Science, University of Massachusetts-Amherst, 111 Totman
Building, 30 Eastman Lane, Amherst, MA 01003-9258, USA.

OBJECTIVE: To investigate the influence of a custom foot orthotic intervention on
the lower extremity dynamics in healthy runners.
DESIGN: Three-dimensional kinematics and kinetics were collected on 15 female
runners (>15 miles per week) while each performed the over-ground running trials
in either a shoe only or a shoe+custom foot orthotic condition. Kinematic and
kinetic variables were analyzed using Paired Sample t-tests.
BACKGROUND: Custom foot orthotics are frequently prescribed treatment modality
for the management of overuse running injuries. Although it is generally accepted
that a custom foot orthotic intervention produces positive clinical outcomes, it
remains unclear what influence this therapeutic modality has on the dynamics of
the lower extremity.
METHODS: Each subject performed five acceptable over-ground running trials (3.6 m
s(-1) +/-5%) with and without the custom foot orthotic intervention in a running
shoe. Selected maximum ankle and knee joint angles and moments were measured
during the stance phase.
RESULTS: While wearing the custom foot orthotic, subjects exhibited significantly
decreased maximum values in rearfoot eversion angle, rearfoot eversion velocity
and internal ankle inversion moment.
CONCLUSIONS: In this sample of healthy female runners, the custom foot orthotic
intervention led to significant decreases in maximum values for ankle dynamics in
the frontal plane and in the sagittal plane of the knee joint. Relevance It
remains unclear how a custom foot orthotic intervention influences lower
extremity dynamics to produce positive clinical outcomes. Furthering our
understanding of the dynamic influence will not only inform improved prescription
and manufacturing practices but may provide insight into the mechanisms that
cause overuse injuries.

PMID: 16603287 [PubMed – indexed for MEDLINE]

J Bone Joint Surg Br. 2006 Jul;88(7):905-8.

A prospective biomechanical study of the association between foot pronation and the incidence of anterior knee pain among military recruits.

Hetsroni I(1), Finestone A, Milgrom C, Sira DB, Nyska M, Radeva-Petrova D, Ayalon
M.

Author information:
(1)Meir Hospital, Sapir Medical Centre, Kfar Saba 44281, Israel.

Excessive foot pronation has been considered to be related to anterior knee pain.
We undertook a prospective study to test the hypothesis that exertional anterior
knee pain is related to the static and dynamic parameters of foot pronation. Two
weeks before beginning basic training lasting for 14 weeks, 473 infantry recruits
were enrolled into the study and underwent two-dimensional measurement of their
subtalar joint displacement angle during walking on a treadmill. Of the 405
soldiers who finished the training 61 (15%) developed exertional anterior knee
pain. No consistent association was found between the incidence of anterior knee
pain and any of the parameters of foot pronation. While a statistically
significant association was found between anterior knee pain and pronation
velocity (left foot, p = 0.05; right foot, p = 0.007), the relationship was
contradictory for the right and left foot. Our study does not support the
hypothesis that anterior knee pain is related to excessive foot pronation.

PMID: 16798993 [PubMed – indexed for MEDLINE]

Res Sports Med. 2006 Apr-Jun;14(2):117-34.

The role of footwear-independent variations in rearfoot movement on impact attenuation in heel-toe running.

Kersting UG(1), Kriwet A, Brüggemann GP.

Author information:
(1)Department of Sport and Exercise Science, The University of Auckland, New
Zealand. u.kersting@auckland.ac.nz

Impact forces and rearfoot eversion have been linked to overuse injuries in
running. Modeling approaches suggest that both factors interact in that reduced
foot eversion relates to increased impact maxima and vice versa. The aim of this
study was to alter rearfoot eversion by applying three different combinations of
ankle taping and bracing. Ten subjects were tested while running at 4 m/s on an
instrumented treadmill. Sagittal plane kinematics, rearfoot eversion, tibial
acceleration, pressure under the heel, and vertical ground reaction force (GRF)
were collected simultaneously over 12 to 14 steps. All interventions reduced the
maximum eversion significantly compared with unrestricted running. The largest
effect was shown for combined bracing and taping, reducing rearfoot movement by
6.1 degrees while impact force varied only marginally. Overall, relationships
between parameters contradict predictions by existing models of foot-ground
interaction. Changes in muscular activation remain as a candidate in the
regulation of impact mechanics in running.

PMID: 16869137 [PubMed – indexed for MEDLINE]

Clin Sports Med. 2006 Jan;25(1):1-16, vii.

The pathophysiology of stress fractures.

Pepper M(1), Akuthota V, McCarty EC.

Author information:
(1)Medical College of Wisconsin, Milwaukee, WI, USA.

Stress fractures can occur in any active individual, from the weekend warrior to
the elite athlete. As these injuries occur, it is important to understand how
bones respond to the stresses placed on them. The understanding of potential
intrinsic and extrinsic causes is important in treatment of these injuries. The
proper identification and prevention of these stress injuries allows for athletes
to return to activity expeditiously.

PMID: 16324969 [PubMed – indexed for MEDLINE]
67. Foot Ankle Int. 2005 Dec;26(12):1081-8.

Shock absorption during forefoot running and its relationship to medial
longitudinal arch height.

Lees A(1), Lake M, Klenerman L.

Author information:
(1)Liverpool John Moores University, Sport and Exercise Sciences, Henry Cotton
Campus, Webster Street, Liverpool L3 2ET, United Kingdom. a.lees@livjm.ac.uk

BACKGROUND: Overuse injuries to the lower extremity have often been connected
with the repetitive loading of the foot and in particular its ability to absorb
shock. The shock absorbing ability of the foot is thought to relate to its
structure, particularly the height of the medial longitudinal arch. The purpose
of this study was to investigate the shock absorption characteristics of the foot
in forefoot running as measured by the dynamic load rate of the vertical ground
reaction forces during the early stages of ground contact and to relate these
characteristics to the height of the medial longitudinal arch.
METHODS: Eighteen normal athletic adult volunteers were used as subjects and all
had clinically normal feet. An Arch Index was computed from lateral radiographs
taken with the foot in a full weightbearing position. Dynamic load rate was
computed as the first differential of the vertical force as measured by a Kistler
force platform. Each subject performed ten trials of running at a speed of 3
m.s-1 using forefoot running style.
RESULTS: The dynamic load rate showed three definite peaks (mean 93, 18, and 16
kNs-1 respectively), and two intervening troughs (mean 18 and 3 kNs-1
respectively), showing that the process of shock absorption was one that was
progressive over the foot loading phase. The time at which these features
occurred indicated a consistency in process of shock absorption. However, none of
the force peaks or load rate peaks correlated with the Arch Index.
CONCLUSION: It was concluded that the structure of the foot as characterized by
the Arch Index, was not the major factor in determining the way in which force is
transmitted to the musculoskeletal system in forefoot running. These findings
support the concept that the height of the arch, although a commonly used
clinical descriptor of foot type does not appear to be important in defining the
functional capacity of the foot in action.

PMID: 16390643 [PubMed – indexed for MEDLINE]

J Appl Biomech. 2005 Nov;21(4):311-21.

Stiffness adaptations in shod running.

Divert C(1), Baur H, Mornieux G, Mayer F, Belli A.

Author information:
(1)Physiology Laboratory, PPEH Unit, University of Saint-Etiene, France.

When mechanical parameters of running are measured, runners have to be accustomed
to testing conditions. Nevertheless, habituated runners could still show slight
evolutions of their patterns at the beginning of each new running bout. This
study investigated runners’ stiffness adjustments during shoe and barefoot
running and stiffness evolutions of shoes. Twenty-two runners performed two
4-minute bouts at 3.61 m.s-1 shod and barefoot after a 4-min warm-up period.
Vertical and leg stiffness decreased during the shoe condition but remained
stable in the barefoot condition, p < 0.001. Moreover, an impactor test showed
that shoe stiffness increased significantly during the first 4 minutes, p <
0.001. Beyond the 4th minute, shoe properties remained stable. Even if runners
were accustomed to the testing condition, as running pattern remained stable
during barefoot running, they adjusted their leg and vertical stiffness during
shoe running. Moreover, as measurements were taken after a 4-min warm-up period,
it could be assumed that shoe properties were stable. Then the stiffness
adjustment observed during shoe running might be due to further habituations of
the runners to the shod condition. To conclude, it makes sense to run at least 4
minutes before taking measurements in order to avoid runners’ stiffness
alteration due to shoe property modifications. However, runners could still adapt
to the shoe.

PMID: 16498177 [PubMed – indexed for MEDLINE]

Int J Sports Med. 2005 Sep;26(7):593-8.

Mechanical comparison of barefoot and shod running.

Divert C(1), Mornieux G, Baur H, Mayer F, Belli A.

Author information:
(1)Laboratory of Physiology, GIP Exercice-Sport-Santé, University of Saint-Etienne,
France. caroline.divert@univ-st-etienne.fr

In order to further compare shod versus barefoot running, 35 subjects ran two
bouts of 4 minutes at 3.33 m x s(-1) on a treadmill dynamometer. Parameters were
measured on about 60 consecutive steps. Barefoot showed mainly lower contact and
flight time (p < 0.05), lower passive peak (1.48 versus 1.70 body weight, p <
0.05), higher braking and pushing impulses (p < 0.05), and higher pre-activation
of triceps surae muscles (p < 0.05) than shod. It was concluded that when
performed on a sufficient number of steps, barefoot running leads to a reduction
of impact peak in order to reduce the high mechanical stress occurring during
repetitive steps. This neural-mechanical adaptation could also enhance the
storage and restitution of elastic energy at ankle extensors level.

PMID: 16195994 [PubMed – indexed for MEDLINE]

J Biomech. 2004 Sep;37(9):1379-86.

Heel-shoe interactions and the durability of EVA foam running-shoe midsoles.

Verdejo R(1), Mills NJ.

Author information:
(1)Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK.
raquel@verdejo.net

A finite element analysis (FEA) was made of the stress distribution in the
heelpad and a running shoe midsole, using heelpad properties deduced from
published force-deflection data, and measured foam properties. The heelpad has a
lower initial shear modulus than the foam (100 vs. 1050 kPa), but a higher bulk
modulus. The heelpad is more non-linear, with a higher Ogden strain energy
function exponent than the foam (30 vs. 4). Measurements of plantar pressure
distribution in running shoes confirmed the FEA. The peak plantar pressure
increased on average by 100% after 500 km run. Scanning electron microscopy shows
that structural damage (wrinkling of faces and some holes) occurred in the foam
after 750 km run. Fatigue of the foam reduces heelstrike cushioning, and is a
possible cause of running injuries.

PMID: 15275845 [PubMed – indexed for MEDLINE]

Can Fam Physician. 2003 Sep;49:1101-9.

Preventing running injuries. Practical approach for family doctors.

Johnston CA(1), Taunton JE, Lloyd-Smith DR, McKenzie DC.

Author information:
(1)camj73@yahoo.ca

OBJECTIVE: To present a practical approach for preventing running injuries.
QUALITY OF EVIDENCE: Much of the research on running injuries is in the form of
expert opinion and comparison trials. Recent systematic reviews have summarized
research in orthotics, stretching before running, and interventions to prevent
soft tissue injuries.
MAIN MESSAGE: The most common factors implicated in running injuries are errors
in training methods, inappropriate training surfaces and running shoes,
malalignment of the leg, and muscle weakness and inflexibility. Runners can
reduce risk of injury by using established training programs that gradually
increase distance or time of running and provide appropriate rest. Orthoses and
heel lifts can correct malalignments of the leg. Running shoes appropriate for
runners’ foot types should be selected. Lower-extremity strength and flexibility
programs should be added to training. Select appropriate surfaces for training
and introduce changes gradually.
CONCLUSION: Prevention addresses factors proven to cause running injuries.
Unfortunately, injury is often the first sign of fault in running programs, so
patients should be taught to recognize early symptoms of injury.

PMCID: PMC2214294
PMID: 14526862 [PubMed – indexed for MEDLINE]

Int J Sports Med. 2001 Aug;22(6):414-9.

Footwear affects the behavior of low back muscles when jogging.

Ogon M(1), Aleksiev AR, Spratt KF, Pope MH, Saltzman CL.

Author information:
(1)Department of Orthopaedic Surgery, University of Innsbruck, Austria.
Michael.Ogon@uibk.ac.at

Use of modified shoes and insole materials has been widely advocated to treat low
back symptoms from running impacts, although considerable uncertainty remains
regarding the effects of these devices on the rate of shock transmission to the
spine. This study investigated the effects of shoes and insole materials on a)
the rate of shock transmission to the spine, b) the temporal response of spinal
musculature to impact loading, and c) the time interval between peak lumbar
acceleration and peak lumbar muscle response. It was hypothesised that shoes and
inserts a) decrease the rate of shock transmission, b) decrease the low back
muscle response time, and c) shorten the time interval between peak lumbar
acceleration and peak lumbar muscle response. Twelve healthy subjects were tested
while jogging barefoot (unshod) or wearing identical athletic shoes (shod).
Either no material, semi-rigid (34 Shore A), or soft (9.5 Shore A) insole
material covered the force plate in the barefoot conditions and was placed as
insole when running shod. Ground reaction forces, acceleration at the third
lumbar level, and erector spinae myoelectric activity were recorded
simultaneously. The rate of shock transmission to the spine was greater (p <
0.0003) unshod (acceleration rate: Means +/- SD 127.35 +/- 87.23 g/s) than shod
(49.84 +/- 33.98 g/s). The temporal response of spinal musculature following heel
strike was significantly shorter (p < 0.023) unshod (0.038 +/- 0.021 s) than shod
(0.047 +/- 0.036 s). The latency between acceleration peak (maximal external
force) and muscle response peak (maximal internal force) was significantly (p <
0.021) longer unshod (0.0137 +/- 0.022s) than shod (0.004 +/- 0.040 s). These
results suggest that one of the benefits of running shoes and insoles is improved
temporal synchronization between potentially destabilizing external forces and
stabilizing internal forces around the lumbar spine.

PMID: 11531033 [PubMed – indexed for MEDLINE]

Med Sci Sports Exerc. 2000 Nov;32(11):1919-26.

Surface effects on ground reaction forces and lower extremity kinematics in running.

Dixon SJ(1), Collop AC, Batt ME.

Author information:
(1)Department of Exercise and Sport Science, University of Exeter, United Kingdom.
s.j.dixon@exeter.ac.uk

INTRODUCTION: Although running surface stiffness has been associated with overuse
injuries, all evidence to support this suggestion has been circumstantial. In the
present study, the biomechanical response of heel-toe runners to changes in
running surface has been investigated.
METHODS: Six heel-toe runners performed shod running trials over three surfaces:
a conventional asphalt surface, a new rubber-modified asphalt surface, and an
acrylic sports surface. The surfaces were categorised according to impact
absorbing ability using standard impact test procedures (BS 7044).
RESULTS: The rubber-modified asphalt was found to exhibit the greatest amount of
mechanical impact absorption, and the conventional asphalt the least. The
comparison of peak impact force values across surfaces for the group of subjects
demonstrated no significant differences in magnitude of force. However, a
significant reduction in loading rate of peak impact force was detected for the
rubber-modified surface compared with conventional asphalt (P < 0.1). Although
analysis of group data revealed no significant differences in kinematic variables
when running on the different surfaces, a varied response to surface manipulation
among runners was demonstrated, with marked differences in initial joint angles,
peak joint angles, and peak joint angular velocities being observed.
DISCUSSION: For some subjects, the maintenance of similar peak impact forces for
different running surfaces was explained by observed kinematic adjustments. For
example, when running on the surface providing the least impact absorption, an
increased initial knee flexion was observed for some subjects, suggesting an
increased lower extremity compliance. However, for some subjects, sagittal plane
kinematic data were not sufficient for the explanation of peak impact force
results. It appears that the mechanism of adaptation varies among runners,
highlighting the requirement of individual subject analyses.

PMID: 11079523 [PubMed – indexed for MEDLINE]

Foot Ankle Int. 2000 Sep;21(9):759-67.

Influence of foot, leg and shoe characteristics on subjective comfort.

Miller JE(1), Nigg BM, Liu W, Stefanyshyn DJ, Nurse MA.

Author information:
(1)Human Performance Laboratory, The University of Calgary, Alberta.
janice@kin.ucalgary.ca

The purpose of this study was to determine the relationships between foot and leg
characteristics, shoe characteristics, and the short-term subjective comfort of
three different pairs of athletic shoes. Static measurements of foot dimension
and leg angles were taken from eighteen subjects. Subjects rated the comfort of
three different athletic shoes for standing, walking and running. The shoes were
quantified by internal dimensions, hardness, flexibility and torsional stiffness.
Average comfort ratings decreased from standing to walking to running. One shoe
seemed suited for only a small group of subjects. In contrast, another shoe was
generally comfortable for a large group. Skeletal alignment, specifically
eversion angle, was related to comfort for one shoe. Therefore, fit of the shoe
is not sufficient for comfort. Skeletal alignment, shoe torsional stiffness and
cushioning seem to be mechanical variables which may be important for comfort.

PMID: 11023224 [PubMed – indexed for MEDLINE]

Sportverletz Sportschaden. 2000 Sep;14(3):82-9.

Energy aspects associated with sport shoes.

Stefanyshyn DJ(1), Nigg BM.

Author information:
(1)Human Performance Laboratory, University of Calgary. darren@kin.ucalgary.ca

Sport shoes can have an influence on the energetics of human movement. The two
main aspects where sport shoes can play a role are in maximizing the energy which
is returned to the athlete and minimizing the energy which is lost by the
athlete. Maximum values of energy storage in a shoe sole are on the order of 10
J. However, not all of this energy is returned to the athlete as shoe midsoles
lose approximately 30% of the energy input. Depending on the movement, energy
return sometimes occurs at the wrong time, frequency, location and in the wrong
direction which compromises the ultimate influence on improving performance. As a
result, the actual influence that energy return has on performance is probably
minimal. Examples of the strategy to minimize energy loss include (1) reducing
the mass of the shoe, (2) using appropriate midsole materials which dissipate
unwanted vibrations, (3) implementing constructions which improve the stability
of the ankle joint and (4) increasing the bending stiffness of shoe midsoles
which reduces the energy lost at the metatarso-phalangeal joint. Energy that has
not been lost for tasks not directly related to the actual performance may be
applied to the movement and may result in an increase of athletic performance. We
propose that athletic footwear can have a much larger influence on performance by
minimizing the energy which is lost as opposed to maximizing the energy which is
returned.

PMID: 11081244 [PubMed – indexed for MEDLINE]

Sportverletz Sportschaden. 2000 Sep;14(3):71-81.

Current issues in the design of running and court shoes.

Reinschmidt C(1), Nigg BM.

Author information:
(1)Human Performance Laboratory, University of Calgary, Canada.
c_reinschmidt@hotmail.com

This review paper focuses on the three most important functional design factors
for sport shoes: injury prevention, performance and comfort. Concepts for these
design factors are discussed for running and court shoes. For running shoes,
pronation control and cushioning are still considered to be the key concepts for
injury prevention despite the fact that conclusive clinical and epidemiological
evidence is missing to show the efficacy of these design strategies. Several
design features have been proposed to be effective in controlling the amount of
pronation. However, the kinematic effects of such features seem to be
subject-specific and rather small especially when looking at the actual skeletal
motion. Recent running shoe research suggests that cushioning may not or only
marginally be related to injuries and that cushioning during the impact phase of
running may be more related to aspects such as comfort, muscle tuning or fatigue.
For court shoes, lateral stability, torsional flexibility, cushioning and
traction control appear to be important design strategies to decrease the risk of
injury. With respect to running performance, the shoe concepts of weight
reduction, efficiency and energy return are discussed. The concept of energy
return does not seem to be a feasible concept whereas concepts which aim to
minimize energy loss appear to be more promising and successful, e.g. weight
reduction, reduction of muscle energy required for stabilization. For court
shoes, optimal traction seems to be the key factor for performance. Research in
the area of shoe comfort is still sparse. Cushioning, fitting and climate
concepts appear to improve the comfort of both running and court shoes. Many
investigations in the area of sport shoe research have shown that
subject-specific responses can be expected. Different groups of athletes may
require different types of shoes. The definition of these grouping
characteristics and their design needs seem to be the most important challenge
for the sport shoe researchers and manufacturers for the near future.

PMID: 11081243 [PubMed – indexed for MEDLINE]

J Biomech. 2000 Mar;33(3):269-78.

Biomechanical analysis of the stance phase during barefoot and shod running.

De Wit B(1), De Clercq D, Aerts P.

Author information:
(1)Department of Movement and Sport Sciences, University of Ghent, Belgium.

This study investigated spatio-temporal variables, ground reaction forces and
sagittal and frontal plane kinematics during the stance phase of nine trained
subjects running barefoot and shod at three different velocities (3.5, 4.5, 5.5 m
s(-1)). Differences between conditions were detected with the general linear
method (factorial model). Barefoot running is characterized by a significantly
larger external loading rate than the shod condition. The flatter foot placement
at touchdown is prepared in free flight, implying an actively induced adaptation
strategy. In the barefoot condition, plantar pressure measurements reveal a
flatter foot placement to correlate with lower peak heel pressures. Therefore, it
is assumed that runners adopt this different touchdown geometry in barefoot
running in an attempt to limit the local pressure underneath the heel. A
significantly higher leg stiffness during the stance phase was found for the
barefoot condition. The sagittal kinematic adaptations between conditions were
found in the same way for all subjects and at the three running velocities.
However, large individual variations were observed between the runners for the
rearfoot kinematics.

PMID: 10673110 [PubMed – indexed for MEDLINE]

J Orthop Sports Phys Ther. 2000 Jan;30(1):21-8; discussion 29-31.

Defective running shoes as a contributing factor in plantar fasciitis in a
triathlete.

Wilk BR(1), Fisher KL, Gutierrez W.

Author information:
(1)Orthopedic Rehabilitation Specialists, Miami, Fla. 33176, USA.
info@defectiveshoe.com

STUDY DESIGN: Case study of a patient who developed plantar fasciitis after
completing a triathlon.
OBJECTIVES: To describe the factors contributing to the injury, describe the
rehabilitation process, including the analysis of defective athletic shoe
construction, and report the clinical outcome.
BACKGROUND: Plantar fasciitis has been found to be a common overuse injury in
runners. Studies that describe causative factors of this syndrome have not
documented the possible influence of faulty athletic shoe construction on the
symptoms of plantar fasciitis.
METHODS AND MEASURES: The patient was a 40-year-old male triathlete who was
followed up for an initial evaluation and at weekly intervals up to discharge 4
weeks after injury and at 1 month following discharge. Perceived heel pain, ankle
strength, and range of motion were the primary outcome measures. Shoe
construction was evaluated to assess the integrity of shoe manufacture and wear
of materials by visual inspection of how shoe parts were glued together, if shoe
parts were assembled with proper relationship to each other, if the shoe sole was
level when resting on a level surface, and if the sole allowed unstable motion.
RESULTS: The patient appeared to have a classic case of plantar fasciitis with a
primary symptom of heel pain at the calcaneal origin of the plantar fascia. On
initial evaluation, right heel pain was a 9 of 10, plantar flexion strength was a
3+/5, and ankle dorsiflexion motion was 10 degrees. One month after discharge,
perceived heel pain was 0, plantar flexion strength was 5/5, and dorsiflexion
motion was 15 degrees and equal to the uninvolved extremity. The right running
shoe construction deficit was a heel counter that was glued into the shoe at an
inward leaning angle, resulting in a greater medial tilt of the heel counter
compared with the left shoe. The patient was taught how to examine the integrity
of shoe manufacture and purchased a new pair of sound running shoes.
CONCLUSIONS: A running shoe manufacturing defect was found that possibly
contributed to the development of plantar fasciitis. Assessing athletic shoe
construction may prevent lower extremity overuse injuries.

PMID: 10705593 [PubMed – indexed for MEDLINE]

Clin Biomech (Bristol, Avon). 1998 Oct;13(7):521-531.

Passive regulation of impact forces in heel-toe running.

Wright IC(1), Neptune RR, van Den Bogert AJ, Nigg BM.

Author information:
(1)Human Performance Laboratory, The University of Calgary, Calgary, Canada.

OBJECTIVE: the purpose of this study was to determine whether passive mechanisms
can account for impact force regulation with changing shoe hardness. DESIGN: A
three-dimensional musculoskeletal model of the lower extremity was developed to
simulate impact in running with two different shoe hardnesses. BACKGROUND:
Considerable research has focused on developing shoe cushioning to reduce impact
forces. However, only minimal changes in peak external impact force have been
observed with changes in shoe hardness. It is hypothesized that passive
mechanisms can regulate impact forces with changing shoe hardness, without
changing muscle activities. METHODS: Initial kinematic inputs for the simulations
were measured from nine male subjects performing heel-toe running. Simulations
were performed with initial conditions and muscle stimulation patterns held
constant while shoe hardness was varied between a hard and a soft condition.
RESULTS: There was no significant difference between the soft and hard shoe peak
impact forces. Peak rates of loading were greater for the hard shoe than the soft
shoe. Muscle forces changed with shoe conditions. For some muscles (including the
tibialis anterior) the forces were greater for the hard shoe, whereas for other
muscles (including the peroneus) forces were greater for the soft shoe condition.
CONCLUSIONS: Peak impact forces with changing shoe conditions can be regulated by
passive mechanical changes without changing muscle activities or kinematics
before touchdown. RELEVANCE: Potential injury causing loads on internal
structures (e.g. muscles, tendons, etc.) during the impact phase of running can
depend upon shoe hardness, but are not reflected in changes in external ground
reaction force.

PMID: 11415830 [PubMed – as supplied by publisher]

Med Sci Sports Exerc. 1997 Oct;29(10):1291-8.

Lower extremity alignment and risk of overuse injuries in runners.

Wen DY(1), Puffer JC, Schmalzried TP.

Author information:
(1)Division of Family Medicine, UCLA, Los Angeles, CA 90095, USA.
dwen@fcm.missouri.edu

A group of 304 runners enrolling in a marathon training program had alignment
measurements performed and completed a questionnaire on training practices and
injuries over the previous 12 months. The alignment measures consisted of arch
index (AI), heel valgus (HV), knee tubercle-sulcus angle (TSA), knee varus (KV),
and leg-length difference (LLD). Results indicated few consistent statistical
associations between these alignment measures and risk of injuries, either
bivariately or multivariately: left AI with hamstring injuries; right AI with
shin injuries; right HV with back injuries; left TSA with ankle injuries; KV with
hip injuries; and LLD with back, ankle, and foot injuries. A few statistically
significant relationships were also found between other training and
anthropometric factors and injuries: mileage with hamstring injuries; interval
training with shin injuries; hard surfaces with back and thigh injuries; shoe use
patterns with foot and overall injuries; and body mass index with heel injuries.
We conclude that lower-extremity alignment is not a major risk factor for running
injuries in our relatively low mileage cohort; however, prospective studies are
necessary to confirm or refute these findings.

PMID: 9346158 [PubMed – indexed for MEDLINE]

Clin Biomech (Bristol, Avon). 1997 Jul;12(5):294-300.

Perceptual and biomechanical variables for running in identical shoe
constructions with varying midsole hardness.

Milani TL(1), Hennig EM, Lafortune MA.

Author information:
(1)Biomechanik — Labor, Sport, Universität Essen, Essen, Germany.

OBJECTIVE: Perceptual ratings of mechanical variables were compared with
biomechanical variables that are related to running injuries. DESIGN: Eight
identical running shoes with a relatively close range of midsole hardness were
used. Ground reaction force (GRF), in-shoe pressure distribution and rearfoot
motion were measured during running. Perceptual ratings were obtained after the
running trials. BACKGROUND: Previous studies reported high correlations between
cushioning perception and biomechanical variables for shoes that featured large
differences in midsole hardness. METHODS: A 15-point categorical rating scale was
used to judge impact severity, pressure magnitude and rearfoot motion in running.
Rating scores were compared with biomechanical variables (GRF, pressure
distribution and pronation values) using regression analyses. RESULTS: Regression
analyses revealed high relations between different biomechanical variables and
the perception scores. The best relation to perception was analysed for the
median power frequency of the vertical GRF (r(2) = 0.97). A negative correlation
(r(2) = 0.54) between the first impact of GRF and the perception of impact
severity could be revealed. CONCLUSION: The present study suggests that the
body’s sensory system seems to differentiate well between impacts of different
frequency content. Based on perceptual abilities, subjects adapt their running
style to avoid high heel impacts.

PMID: 11415737 [PubMed – as supplied by publisher]

Clin Sports Med. 1997 Apr;16(2):249-57.

Footwear and stress fractures.

Frey C.

Author information:
Department of Orthopaedic Surgery, University of Southern California, USA.

Causal factors associated with stress fractures include training errors, exercise
surfaces, footwear, and anatomic abnormalities. Logically, footwear can play an
important role in the development and treatment of stress fractures because foot
loading, structure, and stability have a significant impact on the development of
stress fractures. The important characteristics of athletic shoes in the
development and treatment of stress fractures are reviewed in this article.

PMID: 9238308 [PubMed – indexed for MEDLINE]

Br J Sports Med. 1994 Dec;28(4):256-60.

Kinematic and kinetic parameters associated with running in different shoes.

McNair PJ(1), Marshall RN.

Author information:
(1)Faculty of Health Studies, Auckland Technical Institute, New Zealand.

The characteristics of the midsole were examined in four pairs of running shoes
by a materials test. The variables of interest were the peak acceleration, time
to peak acceleration and the kinetic energy absorbed. Ten subjects then ran at a
recreational jogging pace (3.5 ms-1) barefoot and in the shoes. An accelerometer
secured to the lower tibia was used to measure the peak acceleration and time to
peak acceleration associated with footstrike. Subjects were also videoed and a
kinematic analysis was undertaken at the knee and ankle joints. The results from
the materials test showed that the shoes differed in their midsole
characteristics, however, no significant differences (P > 0.05) were observed in
the peak acceleration and time to peak acceleration during running in shoes.
These variables were significantly greater in the barefoot running condition (P <
0.05), as compared with running in shoes. Small and subtle kinematic differences
were observed between the barefoot and shoe conditions. It appears that the
differences observed between the shoes in the materials test were not sufficient
to elicit the kinematic changes observed between the barefoot and shoe
conditions. It is suggested that runners operate within a ‘kinetic bandwidth’
when responding to impact stresses.

PMCID: PMC1332086
PMID: 7894957 [PubMed – indexed for MEDLINE]

Sportverletz Sportschaden. 1993 Dec;7(4):200-5.

[External stabilizers for the foot].

[Article in German]

Stacoff A(1), Stüssi E.

Author information:
(1)Laboratorium für Biomechanik, ETH Zürich, Schlieren.

The stability in the lateral direction is particularly important in indoor sports
as well as tennis, where the frequency of injury at the lateral aspect of the
ankle is considerably high (according to various sources between 20-30%). The
goal of the present work was to discuss the reasons of instability at the ankle
and the effect of external stabilizers. In a number of investigations the
stability was measured via film analysis during sports activities in barefoot and
shoe conditions. It was concluded that stability and blocking of a movement
cannot be regarded as equal. The latter restricts necessary movements of the foot
at the ankle and may also provoke large internal forces elsewhere. Negative in
respect to stability are stiff and thick shoe soles, positive are: the torsional
ability of the sole, softness of the shoe sole edge, the link between the shaft
and the sole, shaft height, taping and bracing.

PMID: 8146760 [PubMed – indexed for MEDLINE]

Sportverletz Sportschaden. 1993 Dec;7(4):210-5.

[Corrections of and within the athletic shoe].

[Article in German]

Wolpert W(1), Zichner L, Varnai S.

Author information:
(1)Klinik für konservative Orthopädie, Wirbelsäulenklinik Bad Homburg.

The footprint is unique to every human. Because of this, the ideal shoe should be
constructed in such a way as to afford the foot enough space. Many sportsmen
become problems in the lower extremities that can lead to stress fractures
because the industrially made sportshoe is made for the average person. In order
to reduce or even avoid these problems, corrections can be made on the shoe parts
such as on the sole, the heel, the pad or the high-tops. According to the
measurements we have made of the foot with the hydraulic principle according to
Ernst and the use of a special innersole (F-Scan, produced bei Tenscan Inc.).
These have shown that at lower speeds (9 km/h) the shock absorption from the foot
is such as to relieve the tension of the orthostatic system. Where as at higher
speeds (14 km/h) the absorbtion produces more tension leading to an overload on
the foot. This can be measured through the innersole tension and form, so that
even through manipulation compensation cannot be achieved.

PMID: 7908461 [PubMed – indexed for MEDLINE]

Sports Med. 1993 Jan;15(1):66-70.

Treatment of lower extremity injuries with orthotic shoe inserts. An overview.

Gross ML(1), Napoli RC.

Author information:
(1)Orthopaedic and Sports Medicine Associates, Emerson, New Jersey.

Orthotic shoe inserts are very effective in providing symptomatic relief of lower
extremity complaints in running athletes. Inserts adjust the
biomechanical-variables associated with running injuries and reduce the effect of
high stresses produced by running activities. Orthotic treatment is based on an
understanding of complex coupling of rotation of the lower extremity with
pronation and supination of the subtalar joint. Orthotic fabrication is initiated
by determining the neutral position of the foot and obtaining an accurate cast of
this position. Successful treatment with orthotic shoe inserts is dependent on
careful evaluation of the runner and formulation of a properly fitted orthosis.
When correctly utilised, orthotic shoe inserts are beneficial for a broad range
of disorders experienced by runners. Since biomechanical deficits may be related
to injuries along the entire lower extremity, specific diagnoses may be of lesser
indication; however, accurate identification of the underlying biomechanical
deficit is critical. Problems related to excessive or prolonged pronation are
most amenable to orthotic treatment. While treatment of the cavus foot with
orthotic shoe inserts is sometimes worthwhile, the clinician should be aware of
limited success in this instance. Finally, orthotics are only one facet in the
overall treatment plan for injured running athletes. Most overuse syndromes will
respond to rest, training modification, and a change in the running surface or
shoe. Equally important is the use of a proper conditioning and stretching
programme both for injury prevention and for treatment of specific injuries.
Treatment with orthotic shoe inserts should not be used as a substitute for any
of these approaches.

PMID: 8426945 [PubMed – indexed for MEDLINE]

Am J Sports Med. 1991 Jul-Aug;19(4):409-12.

Effectiveness of orthotic shoe inserts in the long-distance runner.

Gross ML(1), Davlin LB, Evanski PM.

Author information:
(1)Orthopaedic and Sports Medicine Associates, Emerson, New Jersey 07675.

Five hundred questionnaires were distributed to long-distance runners who had
used, or who were using orthotic shoe inserts for symptomatic relief of lower
extremity complaints. Three hundred forty-seven (69.4%) responded (males, 71%;
females, 29%). The mean age of the respondents was 36 years (range, 15 to 61).
The average distance run per week was 39.6 miles (range, 5 to 98). The mean
duration for use of the orthotic inserts was 23 months (range, 1 to 96). The
predominant (63%) type of orthotic device used was flexible. The presumed
diagnoses in the population studied were excessive pronation (31.1%), leg length
discrepancy (13.5%), patellofemoral disorders (12.6%), plantar fasciitis (20.7%),
Achilles tendinitis (18.5%), shin splints (7.2%), and miscellaneous (4.9%). Of
the runners responding, 262 (75.5%) reported complete resolution or great
improvement of their symptoms. Results of treatment with orthotic shoe inserts
were independent of the diagnosis or the runner’s level of participation. A high
degree of overall satisfaction was demonstrated by the finding that 90% of the
runners continued to use the orthotic devices even after resolution of their
symptoms. Orthotic shoe inserts were most effective in the treatment of symptoms
arising from biomechanical abnormalities, such as excessive pronation or leg
length discrepancy. Along with other conservative measures, orthotic shoe inserts
may allow the athlete to continue participation in running and avoid other
treatment modalities that are more costly and time consuming, and therefore less
acceptable to them.

PMID: 1897659 [PubMed – indexed for MEDLINE]

Med Sci Sports Exerc. 1991 Feb;23(2):217-24.

Athletic footwear: unsafe due to perceptual illusions.

Robbins SE(1), Gouw GJ.

Author information:
(1)Department of Mechanical Engineering, Concordia University, Montreal, Quebec,
Canada.

Comment in
Med Sci Sports Exerc. 1992 Jan;24(1):144-7.

Modern athletic footwear provides remarkable plantar comfort when walking,
running, or jumping. However, when injurious plantar loads elicit negligible
perceived plantar discomfort, a perceptual illusion is created whereby perceived
impact is lower than actual impact, which results in inadequate impact-moderating
behavior and consequent injury. The objective of this study was to examine how
plantar tactile (mechanical) events affect perceived plantar discomfort. Also, we
evaluated the feasibility of a footwear safety standard we propose, which
requires elimination of the above illusion. Twenty subjects gave numerical
estimates of plantar discomfort produced by simulated locomotion (concurrent
vertical (0.1-0.7 kg.cm-2) and horizontal (0.1-0.9 kg.cm-2) plantar loads), with
the foot supported by either a smooth rigid surface or a rigid surface with 2 mm
high rigid irregularities. Vertical or horizontal load alone evoked no discomfort
(P greater than 0.05), whereas together, discomfort emanated from loads as low as
0.4 kg.cm-2. Irregularities heightened discomfort by a factor of 1.89. This
suggests that the proposed safety standard is feasible, since compliance could be
achieved simply by adding surface irregularities to insoles and by other changes
that heighten localized plantar loads. However, until this standard is adhered
to, it might be more appropriate to classify athletic footwear as “safety
hazards” rather than “protective devices”.

PMID: 2017018 [PubMed – indexed for MEDLINE]

Sportverletz Sportschaden. 1989 Dec;3(4):167-82.

[Torsion –a new concept in construction of sports shoes. Motion excursion of the foot in athletic stress–anatomical and biomechanical observations and their effects on construction of sports shoes].

[Article in German]

Segesser B(1), Stüssi E, von A Stacoff M, Kälin X, Ackermann R.

Author information:
(1)Praxisklinik Rennbahn, Orthopädie und Sportmedizin, Muttenz-Basel.

In recent years several construction elements resulted in an increasing
stiffening of the sport shoe so that the foot was partly forced to make its own
movements inside the shoe. A new sport shoe concept is presented basing on the
results of anatomic and biomechanical studies, its innovative feature being
decoupling of the foot movement between the calcaneal part of the foot and the
metatarsus (= torsion). The foot is given an opportunity to transmit its freedom
of movement in the longitudinal axis of the foot to the shoe without the shoe
acting as a lever, this goal being achieved by a limited liberation of the
metatarsal pronation/supination and a controlled uncoupling of the metatarsus
from the calcaneal part of the foot.

PMID: 2623558 [PubMed – indexed for MEDLINE]

Sportverletz Sportschaden. 1988 Jun;2(2):80-5.

[Running injuries and running shoe construction: demonstration of possible
correlations].

[Article in German]

Kälin VX(1), Denoth J, Stacoff A, Stüssi E.

Author information:
(1)Laboratorium für Biomechanik ETH Zürich.

Previous investigations about the running shoe design demonstrated a relationship
between the geometry of the shoe sole, the ground reaction forces and the foot
movements during impact. Thus, the question arised in which way this relationship
would influence the internal forces. The purpose of this investigation was to
model the impact situation and to simulate different sole geometries in order to
calculate the internal forces and the pronation velocity. The results show that
the geometry has a small effect upon the joint forces, but a very high effect on
the pronation velocity. As a consequence, the joint forces changed only by 10% or
less, but the load of the structures which are stressed by pronation is increased
up to 200%. Thus, the control of the initial pronation is much more important in
current running shoe design than the shock-absorption.

PMID: 3242154 [PubMed – indexed for MEDLINE]

Med Sci Sports Exerc. 1987 Apr;19(2):148-56.

Running-related injury prevention through barefoot adaptations.

Robbins SE, Hanna AM.

A number of reports indicate an extremely low running-related injury frequency in
barefoot populations in contrast to reports about shod populations. It is
hypothesized that the adaptations which produce shock absorption, an inherent
consequence of barefoot activity and a mechanism responsible for the low injury
frequency in unshod populations, are related to deflection of the medial
longitudinal arch of the foot on loading. It is also hypothesized that the known
inability of this arch of the shod foot to deflect without failure (foot
rigidity) is responsible for the high injury frequency in shod populations. To
evaluate these hypotheses, 17 recreational runners were analyzed to study the
adaptive pattern of the medial longitudinal arch of the foot due to increased
barefoot weight-bearing activity. Changes occurred in the medial longitudinal
arch which allowed deflection of this arch on loading which substantiated the
hypotheses. Other evidence suggests that sensory feedback largely from the
glabrous epithelium of the foot is the element of barefoot activity which induced
these adaptations. The sensory insulation inherent in the modern running shoe
appears responsible for the high injury frequency associated with running. The
injuries are considered “pseudo-neuropathic” in nature.

PMID: 2883551 [PubMed – indexed for MEDLINE]

Clin Podiatr Med Surg. 1986 Oct;3(4):649-59.

The biomechanics of running on different surfaces.

Feehery RV Jr.

The ground reaction forces at the foot and the shock transmitted through the body
to the head when running on different surfaces has been presented. Although
differences in the vertical force and acceleration were measured, they appear to
be relatively small. It may be possible that the runner is subconsciously able to
adjust the stiffness of his leg just prior to heel strike based upon his
perception of the hardness of the surface. It is doubtful that differences of
this small magnitude in vertical force would lead to a higher incidence of injury
on a particular surface. More likely to be a causative factor might be the rapid
transmission of the shock wave through the body on a harder surface, like
concrete or asphalt, and the apparent limitation of the runner’s ability to
dampen the high-frequency shock waves as his speed increases.

PMID: 2946394 [PubMed – indexed for MEDLINE]

Am J Sports Med. 1986 Mar-Apr;14(2):151-5.

Injuries to runners: a study of entrants to a 10,000 meter race.

Jacobs SJ, Berson BL.

As the number of runners has increased dramatically, so has the incidence of
running-related injuries. In order to determine what training factors are
associated with running-related injuries, as well as what percentage of injured
runners seeks professional medical attention, a random sample of entrants to a 10
kilometer race was asked to complete a questionnaire. There were 451 respondents,
355 men and 96 women, with a nonresponse rate of 12.7%. Nonrespondents did not
differ from respondents with regard to age or sex. Forty-seven percent of
respondents indicated that they had sustained a running-related injury in the
last 2 years. Injured runners differed significantly from noninjured runners in
that they were more likely to have run more miles per week, run more days per
week, run a faster pace, run more races in the last year, stretched before
running, and not participated regularly in other sports. Associated with injury,
but not statistically significant, were those who had run marathons and had done
muscle-strengthening exercises. No association was found with regard to the
length of time running, running surfaces, part of the foot first contacting the
ground, or running intervals, sprints, or hills. Seventy percent of those injured
sought professional medical care, with 76% of these having a good or excellent
recovery from their injuries. Compliance with medical advice correlated well with
treatment success.

PMID: 3717487 [PubMed – indexed for MEDLINE]

Sports Med. 1985 Sep-Oct;2(5):334-47.

Running shoes, orthotics, and injuries.

McKenzie DC, Clement DB, Taunton JE.

Running is the most visible expression of the continued interest in regular
physical activities. Unfortunately injuries are common, primarily due to overuse,
and a number of aetiological factors have been recognised. Of these, training
errors can be responsible for up to 60% of injuries. The training surface, a lack
of flexibility and strength, the stage of growth and development, poor footwear
and abnormal biomechanical features have all been implicated in the development
of running injuries. A thorough understanding of the biomechanics of running is a
necessary prerequisite for individuals who treat or advise runners. Clinically,
the configuration of the longitudinal arch is a valuable method of classifying
feet and has direct implications on the development and management of running
problems. The runner with excessively pronated feet has features which predispose
him/her to injuries that most frequently occur at the medial aspect of the lower
extremity: tibial stress syndrome; patellofemoral pain syndrome; and posterior
tibialis tendinitis. These problems occur because of excessive motion at the
subtalar joint and control of this movement can be made through the selection of
appropriate footwear, plus orthotic foot control. The runner with cavus feet
often has a rigid foot and concomitant problems of decreased ability to absorb
the force of ground contact. These athletes have unique injuries found most
commonly on the lateral aspect of the lower extremity: iliotibial band friction
syndrome; peroneus tendinitis; stress fractures; trochanteric bursitis; and
plantar fasciitis. Appropriate footwear advice and the use of energy-absorbing
materials to help dissipate shock will benefit these individuals. Running shoes
for the pronated runner should control the excessive motion. The shoes should be
board-lasted, straight-lasted, have a stable heel counter, extra medial support,
and a wider flare than the shoes for the cavus foot. For these athletes a
slip-lasted, curve-lasted shoe with softer ethylene vinyl acetate (EVA) and a
narrow flare is appropriate. Orthotic devices are useful in selected runners with
demonstrated biomechanical abnormalities that contribute to the injury. Soft
orthotics made of a commercial insole laminated with EVA are comfortable, easily
adjusted, inexpensive, and more for-giving than the semirigid orthotics which are
useful in cases where the soft orthotic does not provide adequate foot control. A
review of injury data shows an alarming rise in the incidence of knee pain in
runners-from 18% to 50% of injuries in 13 years.(ABSTRACT TRUNCATED AT 400 WORDS)

PMID: 3850616 [PubMed – indexed for MEDLINE]

Sports Med. 1985 Mar-Apr;2(2):144-53.

The biomechanics of running. Implications for the prevention of foot injuries.

Subotnick SI.

Understanding the biomechanics of running has brought implications for the
prevention of foot injuries. These biomechanical considerations, both functional
and non-functional, must be evaluated by the sports medicine practitioner.
Although functional biomechanical findings are more accurate predictors of injury
and diagnostic tools than static findings, a correlation between the two is
essential. Other important variables, e.g. training methods, athletic shoes,
psychology, general health, external environment (surfaces, weather) and overuse,
must be correlated with the biomechanical findings. The methodology and results
of research are inconsistent with the direct predictability of various overuse
injuries, based on biomechanical abnormalities and/or contributing factors. Until
more research is carried out, clinical experience and the results of structured
research investigations will provide the basis of treatment.

PMID: 2860714 [PubMed – indexed for MEDLINE]

Appl Ergon. 1984 Dec;15(4):281-7.

Physiological and ergonomics factors in running shoe design.

Frederick EC.

Author information:
Nike Sport Research Laboratory, Exeter, New Hampshire.

Various features of the design of running shoes have been known to affect the
performance and safety of athletes. The performance related effects of shoe
design on traction and on the economy of locomotion are reviewed in this paper.
Traction measurements in various types of running shoes and on various surfaces
appear adequate for all but running on wet asphalt roads. Future designs should
improve traction for those conditions. Effects on the economy of locomotion as
small as 1% can be determined using conventional oxygen uptake measurements. The
effect of carrying extra weight on the foot during running has been measured at
1% per 100 g per foot. The cost of carrying similar weights is much lower for
walking or for running when the weight is carried nearer the body’s centre of
mass. Cushioning and other features of shoe design besides weight have been shown
to have significant effects on the economy of locomotion. Optimum designs for
maximising running performance should provide sufficient traction, minimal weight
and maximum cushioning.

PMID: 15676526 [PubMed]

Crit Rev Biomed Eng. 1984;12(1):1-48.

Biomechanics of running gait.

Vaughan CL.

With the recent world-wide upsurge in running, the preponderance of research has
been of a physiological nature. This is understandable when the cardiovascular
benefits are considered. However, the biomechanical component is also very
important, especially when trying to establish the aetiology of various
musculoskeletal injuries or the principles underlying successful technique. In
this paper, therefore, we are concerned with various biomechanical aspects of
sprinting, middle and long distance running, and jogging. The topics covered
include: the class of running gait (sprinting, jogging, ascending/descending,
load carrying, treadmill); electromyography; joints; kinematics (both linear and
angular); kinetics (force place, joint forces and torques, work/energy/power, air
resistance); mathematical techniques and models; orthopedic acids; various
pathologies; different methods of recording motion; and sports footwear and
surfaces. The material should be relevant to both the elite and recreational
athlete.

PMID: 6394212 [PubMed – indexed for MEDLINE]

Int J Sports Med. 1983 Nov;4(4):247-51.

Effects of shoe cushioning upon ground reaction forces in running.

Clarke TE, Frederick EC, Cooper LB.

To determine the effects of widely varying amounts of cushioning upon vertical
force (VF) parameters, ten male subjects, (mean weight = 68.0 kg) ran at a speed
of 4.5 m . s-1 (6 min/mile pace) and contacted a Kistler force platform. Two
shoes were tested: a hard one and a softer shoe that had 50% more cushioning as
measured by an instrumented impact tester. Five right footfalls were collected
for each shoe on each subject during which the ground reaction forces were
sampled at 500 HZ using a PDP 11/34 minicomputer. Eight parameters from the VF
data obtained for each trial were selected for analysis and compared
statistically using a paired difference t test. It was found [force magnitudes
expressed in multiples of body weight (BW)] that the time to the vertical force
impact peak (VFIP) was significantly longer (hard = 22.5 ms, soft = 26.6 ms) in
the soft shoe; however, no differences were seen in the magnitudes (hard = 2.30
BW, soft = 2.34 BW). The minimum after the VFIP was also significantly delayed in
the soft shoe (hard = 33.8 ms, soft = 37.9 ms) and was significantly greater in
the soft shoe (hard = 1.46 BW, soft = 1.90 BW). The peak VF propulsive force
occurred statistically at the same time in both shoes (hard = 85.7 ms, soft =
84.0 ms), but was significantly greater in the soft shoe (hard = 2.73 BW, soft =
2.83 BW).(ABSTRACT TRUNCATED AT 250 WORDS)

PMID: 6654550 [PubMed – indexed for MEDLINE]

JAMA. 1982 Dec 17;248(23):3118-21.

An epidemiologic study of the benefits and risks of running.

Koplan JP, Powell KE, Sikes RK, Shirley RW, Campbell CC.

To better estimate rates of certain benefits and risks of recreational running,
we sent questionnaires to 1,250 randomly selected male and 1,250 female
registrants for a 10-km road race. The response rate was 55% for men and 58% for
women. Telephone interviews of a randomly selected group of nonrespondents
indicated that the only significant differences between respondents and
nonrespondents were that (1) respondents were older than nonrespondents, (2) more
male nonrespondents had stopped running during the year after the race, and (3)
more male nonrespondents had been hit by thrown objects. One year after the race,
89% of male and 79% of female respondents were still running regularly.
Eighty-one percent of men and 75% of women who smoked cigarettes when they began
running had stopped smoking after beginning recreational running. Giving up
smoking was significantly more common for current runners than for “retired”
runners. Weight loss was commonly associated with running and was greater in
those persons who were overweight when they began running. More than a third of
respondents had a musculoskeletal injury attributed to running in the year after
the race and about one seventh of all respondents sought medical consultation for
their injury. The risk of injury increased with increasing weekly mileage. This
study uses epidemiologic methods to quantify some of the benefits and risks of
running.

PMID: 7143687 [PubMed – indexed for MEDLINE]

50% off Running Shoes at Amazon!

Running Shoes Increase Achilles Tendon Load in Walking: an Acoustic Propagation Study.

Changes in lower extremity movement and power absorption during forefoot striking and barefoot running.

Relationships among self-reported shoe type, footstrike pattern, and injury incidence.

Effect of footwear on the external knee adduction moment – A systematic review.

Ground reaction force adaptations during cross-slope walking and running.

Lateral wedge insoles for medial knee osteoarthritis: effects on lower limb frontal plane biomechanics.

Pattern classification of kinematic and kinetic running data to distinguish gender, shod/barefoot and injury groups with feature ranking.

The influence of shoe sole’s varying thickness on lower limb muscle activity.

Shod landing provides enhanced energy dissipation at the knee joint relative to barefoot landing from different heights.

Can orthotic insoles prevent lower limb overuse injuries? A randomized controlled trial of 228 subjects.

Do foot orthoses replicate the static longitudinal arch angle during mid stance in walking?

Effect of a five-toed minimal protection shoe on static and dynamic ankle position sense.

Intravascular haemolysis during prolonged running on asphalt and natural grass in long and middle distance runners.

Barefoot-simulating footwear associated with metatarsal stress injury in 2 runners.

The effect of three different levels of footwear stability on pain outcomes in women runners: a randomised control trial.

Soft tissue thickness under the metatarsal heads is reduced in older people with toe deformities.

Oxygen cost of running barefoot vs. running shod.

Lateral wedge insoles for medial knee osteoarthritis: 12 month randomized controlled trial.

Barefoot running claims and controversies: a review of the literature.

Inter-segment foot kinematics during cross-slope running.

Lower limb joint kinetics in walking: the role of industry recommended footwear.

The natural frequency of the foot-surface cushion during the stance phase of running.

A comparison in the muscle activity of the abductor hallucis and the medial longitudinal arch angle during toe curl and short foot exercises.

Tissue vibration in prolonged running.

Comparative biomechanical effectiveness of over-the-counter devices for individuals with a flexible flatfoot secondary to forefoot varus.

Plantar pressure during running in subjects with chronic ankle instability.

Shoe preference based on subjective comfort for walking and running.

Injury reduction effectiveness of assigning running shoes based on plantar shape in Marine Corps basic training.

Footwear affects the gearing at the ankle and knee joints during running.

Rearfoot eversion has indirect effects on plantar fascia tension by changing the amount of arch collapse.

Repeatability of the Pedar-X in-shoe pressure measuring system.

Prevention of running injuries.

Use of gait sandals for measuring rearfoot and shank motion during running.

Effects of varying amounts of pronation on the mediolateral ground reaction forces during barefoot versus shod running.

Foot strike patterns and collision forces in habitually barefoot versus shod runners.

Hallux valgus and the first metatarsal arch segment: a theoretical biomechanics perspective.

Effects of stride length and running mileage on a probabilistic stress fracture model.

The effect of running shoes on lower extremity joint torques.

Running in new and worn shoes: a comparison of three types of cushioning footwear.

The influence of footwear on foot motion during walking and running.

Computer simulation of the effects of shoe cushioning on internal and external loading during running impacts.

Effect of running shoe type on the distribution and magnitude of plantar pressures in individuals with low- or high-arched feet.

Footwear and running cardio-respiratory responses.

Shoes influence lower limb muscle activity and may predispose the wearer to lateral ankle ligament injury.

Biomechanical and physiological comparison of barefoot and two shod conditions in experienced barefoot runners.

Risk factors for lower extremity injuries among male marathon runners.

Effect of neutral-cushioned running shoes on plantar pressure loading and comfort in athletes with cavus feet: a crossover randomized controlled trial.

Short- and long-term influences of a custom foot orthotic intervention on lower extremity dynamics.

Acute and overuse injuries correlated to hours of training in master running athletes.

Barefoot-shod running differences: shoe or mass effect?

Do you get value for money when you buy an expensive pair of running shoes?

Foot motion in children shoes: a comparison of barefoot walking with shod walking in conventional and flexible shoes.

Long distance running increases plantar pressures beneath the metatarsal heads: a barefoot walking investigation of 200 marathon runners.

Effect of cushioned insoles on impact forces during running.

Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review.

Foot strike patterns of runners at the 15-km point during an elite-level half marathon.

Effect of footwear on high and low arched runners’ mechanics during a prolonged run.

Forefoot-rearfoot coupling patterns and tibial internal rotation during stance phase of barefoot versus shod running.

Interaction of arch type and footwear on running mechanics.

Athletic footwear, leg stiffness, and running kinematics.

Influence of a custom foot orthotic intervention on lower extremity dynamics in healthy runners.

A prospective biomechanical study of the association between foot pronation and the incidence of anterior knee pain among military recruits.

The role of footwear-independent variations in rearfoot movement on impact attenuation in heel-toe running.

The pathophysiology of stress fractures.

Stiffness adaptations in shod running.

Mechanical comparison of barefoot and shod running.

Heel-shoe interactions and the durability of EVA foam running-shoe midsoles.

Preventing running injuries. Practical approach for family doctors.

Footwear affects the behavior of low back muscles when jogging.

Surface effects on ground reaction forces and lower extremity kinematics in running.

Influence of foot, leg and shoe characteristics on subjective comfort.

Energy aspects associated with sport shoes.

Current issues in the design of running and court shoes.

Biomechanical analysis of the stance phase during barefoot and shod running.

Defective running shoes as a contributing factor in plantar fasciitis in a triathlete.

Passive regulation of impact forces in heel-toe running.

Lower extremity alignment and risk of overuse injuries in runners.

Perceptual and biomechanical variables for running in identical shoe constructions with varying midsole hardness.

Footwear and stress fractures.

Relationships among self-reported shoe type, footstrike pattern, and injury
incidence.

Effect of a five-toed minimal protection shoe on static and dynamic ankle
position sense.

Effect of running shoe type on the distribution and magnitude of plantar
pressures in individuals with low- or high-arched feet.

Defective running shoes as a contributing factor in plantar fasciitis in a
triathlete.

Perceptual and biomechanical variables for running in identical shoe
constructions with varying midsole hardness.

[Running injuries and running shoe construction: demonstration of possible
correlations].