J Foot Ankle Res. 2013 Nov 6;6(1):45. doi: 10.1186/1757-1146-6-45.

A comparison of gait biomechanics of flip-flops, sandals, barefoot and shoes.

Zhang X, Paquette MR, Zhang S(1).

Author information:
(1)Department of Kinesiology, Recreation and Sport Study, The University of
Tennessee, Knoxville, TN 37996-2700, USA. szhang@utk.edu.

BACKGROUND: Flip-flops and sandals are popular choices of footwear due to their
convenience. However, the effects of these types of footwear on lower extremity
biomechanics are still poorly understood. Therefore, the objective of this study
was to investigate differences in ground reaction force (GRF), center of pressure
(COP) and lower extremity joint kinematic and kinetic variables during
level-walking in flip-flops, sandals and barefoot compared to running shoes.
METHODS: Ten healthy males performed five walking trials in the four footwear
conditions at 1.3 m/s. Three-dimensional GRF and kinematic data were
simultaneously collected.
RESULTS: A smaller loading rate of the 1st peak vertical GRF and peak propulsive
GRF and greater peak dorsiflexion moment in early stance were found in shoes
compared to barefoot, flip-flops and sandals. Barefoot walking yielded greater
mediolateral COP displacement, flatter foot contact angle, increased ankle
plantarflexion contact angle, and smaller knee flexion contact angle and range of
motion compared to all other footwear.
CONCLUSIONS: The results from this study indicate that barefoot, flip-flops and
sandals produced different peak GRF variables and ankle moment compared to shoes
while all footwear yield different COP and ankle and knee kinematics compared to
barefoot. The findings may be helpful to researchers and clinicians in
understanding lower extremity mechanics of open-toe footwear.

PMCID: PMC3907140
PMID: 24196492 [PubMed]

Med Sci Sports Exerc. 2013 Jul;45(7):1363-8. doi: 10.1249/MSS.0b013e3182874769.

Foot bone marrow edema after a 10-wk transition to minimalist running shoes.

Ridge ST(1), Johnson AW, Mitchell UH, Hunter I, Robinson E, Rich BS, Brown SD.

Author information:
(1)Brigham Young University, Provo, UT 84602, USA. sarah_ridge@byu.edu

PURPOSE: Minimalist running shoes are becoming a more popular choice for runners
in the past few years. However, there is little conclusive evidence about the
advantages or disadvantages of running in these shoes. Although performance
benefits may exist, injury may also occur from the added stress of running
without the benefit of cushioning under the foot. Bone marrow edema can be a
manifestation of added stress on the foot. This study measured bone marrow edema
in runners’ feet before and after a 10-wk period of transitioning from
traditional to minimalist running shoes.
METHODS: Thirty-six experienced recreational runners underwent magnetic resonance
imaging (MRI) before and after a 10-wk period. Seventeen subjects were in the
control group (ran in their traditional shoes only for 10 wk), whereas the other
19 were in the experimental group (gradually transitioned to Vibram FiveFinger
running shoes for 10 wk). The severity of the bone marrow edema was scored on a
range of 0-4 (0 = no bone marrow edema, 4 = edema in more than 50% of the length
of the bone). A score of 4 represented a stress fracture.
RESULTS: Pretraining MRI scores were not statistically different between the
groups. The posttraining MRI scores showed that more subjects in the Vibram group
(10 of 19) showed increases in bone marrow edema in at least one bone after 10 wk
of running than that in the control group (P = 0.009).
CONCLUSION: Runners interested in transitioning to minimalist running shoes, such
as Vibram FiveFingers, should transition very slowly and gradually to avoid
potential stress injury in the foot.

PMID: 23439417 [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

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.

Copyright © 2011 Elsevier B.V. All rights reserved.

PMID: 21733696 [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]

Physiotherapy. 2011 Sep;97(3):250-5. doi: 10.1016/j.physio.2010.08.013. Epub 2011
Feb 2.

Effect of motion control running shoes compared with neutral shoes on tibial
rotation during running.

Rose A(1), Birch I, Kuisma R.

Author information:
(1)Division of Physiotherapy, School of Health Professions, University of Brighton,
UK. alice2rose@googlemail.com

OBJECTIVE: To determine whether a motion control running shoe reduces tibial
rotation in the transverse plane during treadmill running.
DESIGN: An experimental study measuring tibial rotation in volunteer participants
using a repeated measures design.
SETTING: Human Movement Laboratory, School of Health Professions, University of
PARTICIPANTS: Twenty-four healthy participants were tested. The group comprised
males and females with size 6, 7, 9 and 11 feet. The age range for participants
was 19 to 31 years.
MAIN OUTCOME MEASURES: The total range of proximal tibial rotation was measured
using the Codamotion 3-D Movement Analysis System.
RESULTS: A one-tailed paired t-test indicated a statistically significant
decrease in the total range of proximal tibial rotation when a motion control
shoe was worn (mean difference 1.38°, 95% confidence interval 0.03 to 2.73,
CONCLUSIONS: There is a difference in tibial rotation in the transverse plane
between a motion control running shoe and a neutral running shoe. The results
from this study have implications for the use of supportive running shoes as a
form of injury prevention.

Copyright © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd.
All rights reserved.

PMID: 21820544 [PubMed – indexed for MEDLINE]

BMC Res Notes. 2011 Aug 24;4:307. doi: 10.1186/1756-0500-4-307.

Are old running shoes detrimental to your feet? A pedobarographic study.

Rethnam U(1), Makwana N.

Author information:
(1)Department of Orthopaedics, Glan Clwyd Hospital, Rhyl, UK. ulfinr@yahoo.com.

BACKGROUND: Footwear characteristics have been implicated in fatigue and foot
pain. The recommended time for changing running shoes is every 500 miles. The aim
of our study was to assess and compare plantar peak pressures and pressure time
integrals in new and old running shoes.
FINDINGS: This was a prospective study involving 11 healthy female volunteers
with no previous foot and ankle problems. New running shoes were provided to the
participants. Plantar pressures were measured using the Novel Pedar system while
walking with new and participants’ personal old running shoes. Plantar pressures
were measured in nine areas of the feet. Demographic data, age of old running
shoes, Body Mass Index (BMI), peak pressures and pressure-time integral were
acquired. The right and left feet were selected at random and assessed
separately. Statistical analysis was done using the paired t test to compare
measurements between old and new running shoes.The mean peak pressures were
higher in new running shoes (330.5 ± 79.6 kiloPascals kPa) when compared to used
old running shoes (304 ± 58.1 kPa) (p = 0.01). The pressure-time integral was
significantly higher in the new running shoes (110 ± 28.3 kPa s) compared to used
old running shoes (100.7 ± 24.0 kPa s) (p = 0.01).
CONCLUSION: Plantar pressure measurements in general were higher in new running
shoes. This could be due to the lack of flexibility in new running shoes. The
risk of injury to the foot and ankle would appear to be higher if running shoes
are changed frequently. We recommend breaking into new running shoes slowly using
them for mild physical activity.

PMCID: PMC3228510
PMID: 21864342 [PubMed]

Orthopedics. 2011 Jul 7;34(7):e320-3. doi: 10.3928/01477447-20110526-25.

Barefoot-simulating footwear associated with metatarsal stress injury in 2

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.

Copyright 2011, SLACK Incorporated.

PMID: 21717998 [PubMed – indexed for MEDLINE]

Cochrane Database Syst Rev. 2011 Jul 6;(7):CD001256. doi:

Interventions for preventing lower limb soft-tissue running injuries.

Yeung SS(1), Yeung EW, Gillespie LD.

Author information:
(1)Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hung
Hom, Kowloon, Hong Kong, China.

Comment in
Eur J Phys Rehabil Med. 2011 Sep;47(3):507-11.

Update of
Cochrane Database Syst Rev. 2001;(3):CD001256.

BACKGROUND: Overuse soft-tissue injuries occur frequently in runners. Stretching
exercises, modification of training schedules, and the use of protective devices
such as braces and insoles are often advocated for prevention. This is an update
of a review first published in 2001.
OBJECTIVES: To assess the effects of interventions for preventing lower limb
soft-tissue running injuries.
SEARCH STRATEGY: We searched the Cochrane Bone, Joint and Muscle Trauma Group
Specialised Register (March 2011); The Cochrane Library 2010, Issue 4; MEDLINE
(1966 to January 2011); EMBASE (1980 to January 2011); and international trial
registries (17 January 2011).
SELECTION CRITERIA: Randomised or quasi-randomised trials evaluating
interventions to prevent lower limb soft-tissue running injuries.
DATA COLLECTION AND ANALYSIS: Two authors independently assessed risk of bias
(relating to sequence generation, allocation concealment, blinding, incomplete
outcome data) and extracted data. Data were adjusted for clustering if necessary
and pooled using the fixed-effect model when appropriate.
MAIN RESULTS: We included 25 trials (30,252 participants). Participants were
military recruits (19 trials), runners from the general population (three
trials), soccer referees (one trial), and prisoners (two trials). The
interventions tested in the included trials fell into four main preventive
strategies: exercises, modification of training schedules, use of orthoses, and
footwear and socks. All 25 included trials were judged as ‘unclear’ or ‘high’
risk of bias for at least one of the four domains listed above.We found no
evidence that stretching reduces lower limb soft-tissue injuries (6 trials; 5130
participants; risk ratio [RR] 0.85, 95% confidence interval [95% CI] 0.65 to
1.12). As with all non-significant results, this is compatible with either a
reduction or an increase in soft-tissue injuries. We found no evidence to support
a training regimen of conditioning exercises to improve strength, flexibility and
coordination (one trial; 1020 participants; RR 1.20, 95% CI 0.77 to 1.87).We
found no evidence that a longer, more gradual increase in training reduces
injuries in novice runners (one trial; 486 participants; RR 1.02, 95% CI 0.72 to
1.45). There was some evidence from a poor quality trial that additional training
resulted in a significant increase in the number of naval recruits with shin
splints (one trial; 1670 participants; RR 2.02, 95% CI 1.11 to 3.70). There was
limited evidence that injuries were less frequent in prisoners when running
duration (one trial; 69 participants; RR 0.41, 95% CI 0.21 to 0.79) or frequency
(one trial; 58 participants; RR 0.19, 95% CI 0.06 to 0.66) were
reduced.Patellofemoral braces appear to be effective for preventing anterior knee
pain (two trials; 227 participants; RR 0.41, 95% CI 0.24 to 0.67).Custom-made
biomechanical insoles may be more effective than no insoles for reducing shin
splints (medial tibial stress syndrome) in military recruits (one trial; 146
participants; RR 0.24, 95% CI 0.08 to 0.69).We found no evidence in military
recruits that wearing running shoes based on foot shape, rather than standard
running shoes, significantly reduced rate of running injuries (2 trials; 5795
participants; Rate Ratio 1.03, 95% CI 0.93 to 1.14).
AUTHORS’ CONCLUSIONS: Overall, the evidence base for the effectiveness of
interventions to reduce soft-tissue injury after intensive running is very weak,
with few trials at low risk of bias. More well-designed and reported RCTs are
needed that test interventions in recreational and competitive runners.

PMID: 21735382 [PubMed – indexed for MEDLINE]

Hum Mov Sci. 2011 Jun;30(3):606-13. doi: 10.1016/j.humov.2010.10.008. Epub 2011
Feb 17.

Comparison of longitudinal biomechanical adaptation to shoe degradation between the dominant and non-dominant legs during running.

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

Author information:
(1)Department of Kinesiology, University of Texas at El Paso, USA.

This study compared the biomechanical adaptation to running shoe degradation
between the dominant (D) and non-dominant (ND) leg. Twenty-four runners performed
a pre-test in the laboratory, completed 200 miles of road running in a pair of
assigned shoes and then returned for a post-test. Kinetic and kinematic data of
running in new and worn shoes were collected. Repeated measures ANOVA (Shoe×Leg)
were used to analyze temporal, kinetic and kinematic variables (α=.05). A
symmetry index (SI) was calculated for the temporal and kinetic variables and
paired t-tests were used to compare the SI between shoe conditions. Stance time
increased by approximately 7 ms in worn shoes (p=.027). Bilateral differences in
the kinematic change (Shoe×Leg interaction) were seen in the torso (p<.05), knee
(p<.05), marginally at the hip (p<.10) but not the ankle. No difference in
kinetic variables or SI was observed. When running in worn shoes, the torso
displayed reduced forward lean for both sides and to a greater extent during the
D leg strike. The D hip and knee showed a more extended position for the worn
shoe condition while an increased flexion was observed in the ND leg. Most of the
kinematic differences observed were small and within the intra-subject
variability measured during the same session. Future studies may consider
performing a three-dimensional analysis at a higher sample rate and further
explore whether asymmetrical adaptation is related to running injuries.

Copyright © 2011 Elsevier B.V. All rights reserved.

PMID: 21333368 [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.

© Georg Thieme Verlag KG Stuttgart · New York.

PMID: 21472628 [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]

J Biomech. 2011 Mar 15;44(5):984-7. doi: 10.1016/j.jbiomech.2010.11.032. Epub
2010 Dec 14.

An improved cost function for modeling of muscle activity during running.

Nikooyan AA(1), Zadpoor AA.

Author information:
(1)Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and
Materials Engineering, Delft University of Technology, Mekelweg 2, Delft 2628 CD,
The Netherlands.

This paper tries to improve a recently developed mass-spring-damper model of the
human body during running. The previous model took the muscle activity into
account using a nonlinear controller that tuned the mechanical properties of the
soft-tissue package based on two physiological hypotheses, namely
“constant-force” and “constant-vibration”. Three cost functions were used, out of
which one was based on the constant-force hypothesis and two others were based on
the constant-vibration hypothesis. The results of the study showed that the
proposed cost functions are only partially successful in capturing the
experimentally observed trends of the ground reaction force and vibration. The
current paper proposes an improved cost function that combines both
above-mentioned hypotheses. It is shown that the improved cost function can
capture all the trends that were observed in the measurements of the ground
reaction force and vibration level. It is therefore advised to use the new cost
function in place of the previous ones.

Copyright © 2010 Elsevier Ltd. All rights reserved.

PMID: 21159342 [PubMed – indexed for MEDLINE]


J Sports Sci. 2011 Feb;29(4):373-9. doi: 10.1080/02640414.2010.534805.

Changes in running mechanics using conventional shoelace versus elastic shoe

Hong Y(1), Wang L, Li JX, Zhou JH.

Author information:
(1)Department of Sports Medicine, Chengdu Sports University, Chengdu, China.

The purpose of this study was to determine whether there are differences in the
perceived comfort, plantar pressure, and rearfoot motion between laced running
shoes and elastic-covered running shoes. Fifteen male amateur runners
participated in the study. Each participant was assigned laced running shoes and
elastic-covered running shoes for use during the study. The perceived comfort,
plantar loading, and rearfoot motion control of each type of shoes during running
were recorded. When the laced running shoes and elastic-covered running shoes
were compared, the elastic-covered running shoes were given a lower perceived
comfort rating in terms of shoe length, width, heel cup fitting, and forefoot
cushioning. The elastic-covered running shoes also recorded higher peak plantar
pressure in the lateral side of the forefoot, as well as larger maximum rearfoot
pronation. Overall, shoelaces can help runners obtain better foot-shoe fit. They
increase the perceived comfort, and decrease the maximum pronation and plantar
pressure. Moreover, shoelaces may help prevent injury in running by allowing
better control of the aforementioned factors.

PMID: 21184340 [PubMed – indexed for MEDLINE]

J Physiother. 2011;57(3):195. doi: 10.1016/S1836-9553(11)70043-1.

Lateral wedge insoles worn for 12 months provided no symptomatic or structural
benefit for people with medial knee osteoarthritis.

Snyder-Mackler L.

Author information:
University of Delaware, USA.

Comment on
BMJ. 2011;342:d2912.

PMID: 21843837 [PubMed – indexed for MEDLINE]

J Appl Biomech. 2010 Nov;26(4):390-9.

Influence of custom foot orthotic intervention on lower extremity intralimb
coupling during a 30-minute run.

MacLean CL(1), van Emmerik R, Hamill J.

Author information:
(1)Biomechanics Laboratory, Department of Kinesiology, University of
Massachusetts-Amherst, Amherst, MA, USA.

The purpose of this study was to analyze the influence of a custom foot orthotic
(CFO) intervention on lower extremity intralimb coupling during a 30-min run in a
group of injured runners and to compare the results to a control group of healthy
runners. Three-dimensional kinematic data were collected during a 30-min run on
healthy female runners (Shoe-only) and a group of female runners who had a recent
history of overuse injury (Shoe-only and Shoe with custom foot orthoses). Results
from the study revealed that the coordination variability and pattern for the
some couplings were influenced by history of injury, foot orthotic intervention
and the duration of the run. These data suggest that custom foot orthoses worn by
injured runners may play a role in the maintenance of coordination variability of
the tibia (transverse plane) and calcaneus (frontal plane) coupling during the
Early Stance phase. In addition, it appears that the coupling angle between the
knee (transverse plane) and rearfoot (frontal plane) joints becomes more
symmetrical in the late stance phase as a run progresses.

PMID: 21245498 [PubMed – indexed for MEDLINE]

J Sports Sci Med. 2010 Mar 1;9(1):147-53. eCollection 2010.

Ground reaction force differences between running shoes, racing flats, and distance spikes in runners.

Logan S(1), Hunter I, J Ty Hopkins JT, Feland JB, Parcell AC.

Author information:
(1)Brigham Young University , Provo, UT, USA.

Various shoes are worn by distance runners throughout a training season. This
study measured the differences in ground reaction forces between running shoes,
racing flats, and distance spikes in order to provide information about the
potential effects of footwear on injury risk in highly competitive runners. Ten
male and ten female intercollegiate distance runners ran across a force plate at
6.7 m·s(-1) (for males) and 5.7 m·s(-1) (for females) in each of the three types
of shoes. To control for differences in foot strike, only subjects who exhibited
a heel strike were included in the data analysis. Two repeated-measures ANOVAs
with Tukey’s post-hoc tests (p < 0.05) were used to detect differences in shoe
types among males and females. For the males, loading rate, peak vertical impact
force and peak braking forces were significantly greater in flats and spikes
compared to running shoes. Vertical stiffness in spikes was also significantly
greater than in running shoes. Females had significantly shorter stance times and
greater maximum propulsion forces in racing flats compared to running shoes.
Changing footwear between the shoes used in this study alters the loads placed on
the body. Care should be taken as athletes enter different phases of training
where different footwear is required. Injury risk may be increased since the body
may not be accustomed to the differences in force, stance time, and vertical
stiffness. Key pointsTo determine the differences in ground reaction forces
between regular running shoes and competitive footwear, force plate data was
obtained from 10 males (6.7 m·s(-1)) and 10 females (5.7 m·s(-1)) for each of
three shoe types.Data from men and women were analyzed in two separate groups,
and significant differences were found for various GRF components between the
three types of shoes.The significant increases in GRF components in competitive
footwear suggest that the body must deal with greater impact forces in these
shoes than in running shoes at the same running speed.The results from this study
warrant the recommendation that runners transition gradually from periods when
most or all of their training is done in running shoes to more competitive
seasons when more of their training is done in racing flats and spikes.

PMCID: PMC3737977
PMID: 24149399 [PubMed]

J Biomech. 2000 Nov;33(11):1387-95.

Tibiocalcaneal kinematics of barefoot versus shod running.

Stacoff A(1), Nigg BM, Reinschmidt C, van den Bogert AJ, Lundberg A.

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

Barefoot running kinematics has been described to vary considerably from shod
running. However, previous investigations were typically based on externally
mounted shoe and/or skin markers, which have been shown to overestimate skeletal
movements. Thus, the purpose of this study was to compare calcaneal and tibial
movements of barefoot versus shod running using skeletal markers. Intracortical
bone pins with reflective marker triads were inserted under standard local
anesthetic into the calcaneus and tibia of five healthy male subjects. The
subjects ran barefoot, with a normal shoe, with three shoe soles and two orthotic
modifications. The three-dimensional tibiocalcaneal rotations were determined
using a joint coordinate system approach. Test variables were defined for
eversion and tibial rotation. The results showed that the differences in bone
movements between barefoot and shod running were small and unsystematic (mean
effects being less than 2 degrees ) compared with the differences between the
subjects (up to 10 degrees ). However, differences may occur during midstance
when extreme shoe modifications (i.e. posterior orthosis) are used. It is
concluded that calcaneal and tibial movement patterns do not differ substantially
between barefoot and shod running, and that the effects of these interventions
are subject specific. The result of this in vivo study contrasts with previous
investigations using skin and shoe mounted markers and suggests that these
discrepancies may be the result of the overestimation with externally mounted

PMID: 10940397 [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.

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]

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]

21. J Biomech. 1993;26 Suppl 1:41-51.

The energetics of running and running shoes.

Shorten MR.

It has been suggested that elastic energy storage and recovery in the cushioning
system of an athletic shoe (‘energy return’) is a desirable quality that can
enhance performance. However, comparing the energetics of a running shoe
cushioning system with other passive energy exchange mechanisms in the running
athlete suggests that the potential benefits of energy return are limited. The
energetics of running shoe cushioning systems have been studied using a
multiple-element, non-linear viscoelastic model to analyse the effect on the shoe
of plantar pressure distributions recorded in vivo. The running shoe is a net
dissipator of energy but small quantities of strain energy, of the order of 10J,
are stored and recovered during a running step. The actual energy exchanges
depend on the cushioning material properties and the runner’s plantar pressure
distribution. Energy storage and recovery occurs throughout the step in different
regions of the shoe midsole. Energy dissipation is confined almost entirely, both
spatially and temporally, to the impact phase of ground contact. Thus the
proportion of input energy recovered from the shoe is higher than that predicted
by mechanical tests which stimulate only the impact phase of the step. Energy
storage and recovery in the model shoe are large enough to have local effects on
the energetics of the foot and lower leg but modest when compared with passive
energy transfer within and between body segments or strain energy storage and
recovery in the lower limb. Similarly, differences in the energy dissipated by
well-designed shoes are predicted to be small and unlikely to have a direct
effect on the energetics of the body as a whole. The possibility of indirect,
kinematically mediated effects remains open, however.

PMID: 8505351 [PubMed – indexed for MEDLINE]

Med Sci Sports Exerc. 1992 May;24(5):595-602.

Biomechanical and orthopedic concepts in sport shoe construction.

Nigg BM(1), Segesser B.

Author information:
(1)Biomechanics Laboratory, University of Calgary, Alberta, Canada.

Two sets of concepts for sport shoe construction are discussed, based on
anatomical, orthopedic, and epidemiological considerations: one for the
prevention of excessive load and related injuries, and one for the improvement of
performance. The proposed concepts for prevention of excessive load and related
injuries in the foot and the lower extremities are cushioning, support, and
guidance. The goals outlined in the concepts can be achieved by altering the
material properties or the construction of the shoe. It is suggested that the
concept “cushioning” is not well understood yet and needs further research. The
discussed concepts for improving performance are first, that energy should be
returned at the right location, at the right time, with the right frequency, and
second, that loss of energy should be minimized. Reduction of energy loss is an
important concept for performance. The concept “return of energy” seems
inappropriate for sport shoes.

PMID: 1569856 [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]