The first issue of the Natural Born Runner Magazine out of the UK is hitting the shelves this month. This is the first magazine dedicated to natural/minimalist/barefoot running. I am very excited to be a member of the editorial panel along with Daniel Leiberman, Irene Davis, Mark Cucuzzella, and other great researchers and runners. You can read a PDF of the first magazine online here. I have also posted my article below. Enjoy!
TREATING RUNNING INJURIES: FORM VS FOOTWEAR
Running injuries can be very frustrating for physicians, as such injuries can be extremely time consuming and the stereotypical runner will not curtail running to resolve an injury. If you tell a runner not to run, most of the time he or she will not listen to you and not follow through with your prescribed treatment regimen. This challenge leads many physicians to not treat runners. Added to this frustration is the recommendation of shoe gear. Whether someone has been running for many years or is just starting out, he or she will tend to place a lot of emphasis on what shoes to wear. Form is traditionally ignored. Runners, as well as practitioners, will typically make a change their shoes in an attempt to fix an injury.
What most practitioners do not realise is that there is no evidence-based literature on recommending a running shoe to prevent or reduce injury (Footnotes 1 to 8).
Following the popular paradigm of recommending a running shoe based on foot type leads to frustration, as numerous models are introduced frequently. Not only does this complicate matters, but when we analyse the reasons that we use a particular shoe, the situation becomes even more blurred.
There exists no clear scientific basis for using one particular shoe model over another for given foot types or pathologies, despite what some manufacturers claim (1). The term ‘appropriate shoe’ is a misnomer when judged by the outdated paradigm of selecting a shoe according to arch type, yet many still advocate shoes this way. Even the implementation of orthotics has little if any bearing on reducing or correcting injuries in runners (9 to 12).
We also live in a society where some people incorrectly believe they have a flat foot or are over-pronated. Associated with this is the stigma that foot types (especially flat feet) influence injury patterns (13). This, however, is not true (14). Evidence suggests that training patterns actually play more of a role in increasing the incidence of running injuries (15 and 16). The key is understanding that form and training patterns play more of a role in improving one’s running and at the same time reducing injury (17).
Before seeking treatment for an injury, most runners will run through the pain, thinking that it will eventually resolve itself. When the pain finally becomes too severe to allow the runner to continue, medical advice is usually sought.
The standard protocol for a physician or sports medicine specialist treating a runner is as follows: 1) Ask the athlete how many miles a week he or she is running. 2) Evaluate shoe gear. 3) Find out the number of miles on the current shoe gear. 4) Carry out a biomechanical assessment of the feet and lower extremities. If the runner is seen in a more specialised clinic, gait analysis is sometimes performed. Overpronation is commonly diagnosed and an effort to control this excessive motion is usually attempted with orthotics. High-tech scans and pressure analysis may also be performed, although very little if any applicable information can be generated from this.
Form analysis, on the contrary, focuses more on the runner’s style with respect to foot strike, cadence and the runner’s overall body posture. Form analysis is slowly becoming a panacea to help improve someone’s running and reduce or resolve injuries (17 and 18). Runners tend to develop injuries as a result of poor or incorrect form and overuse, which many times overlap (15 and 19). Debate exists as to what is the ‘proper form’ for running. Proper form will certainly vary from one runner to the next, making each runner’s form ‘ideal’ for him or her. There are, however, certain aspects of form a runner should strive to attain: adequate foot strike, cadence and posture.
Foot strike is the first aspect that needs to be addressed. There exists a common misunderstandings hat all aspects of gait, whether walking or running, should begin with a heel strike. Following heel strike, the force is carried toward the outside edge of the foot and then moves inward to the great toe joint. There, a large amount of force is created to propel the body forward. Much of this is attributed to Root et al, in their discussion of walking mechanics, which over the years has somehow carried over to running (20). The practitioner sometimes will examine the shoe gear to see if any wear patterns exists that would indicate increased pronation, as indicated by wear seen more on the inside of the heel than on the outside.
The problem with this pathway is that we have no evidence- based studies to indicate that heel striking is the correct way to land when running. In fact, recent studies demonstrate higher injuries amongst collegiate cross-country runners that heel strike than among those who forefoot strike (21 and 22).
Numerous studies have compared shod and unshod runners and a forefoot strike pattern is adapted among those who run without shoes (23 to 27). We all see that elite runners tend to forefoot strike more than slower recreational runners, as demonstrated by Larson et al (28 and 29). Evidence exists that the human body has a natural tendency to forefoot or midfoot strike when running barefoot or in minimalist shoes (23 and 26).
Heel strike vs forefoot/midfoot strike
By striking the ground with the heel first, the rear foot joints and ankle take the brunt of the force, which overuses the lower leg muscles, leading to injuries such as severe tendonitis or conditions commonly called ‘shin splints’. We also see that during a rearfoot strike, the forefoot (including the toes) and midfoot joints really serve no purpose in absorbing shock. If, instead, we use these joints with a forefoot or midfoot strike, the entire foot can work to absorb shock, as opposed to only the rear foot joints and leg (30). When we forefoot or midfoot strike, we can control the amount of pronation innately by activating our leg musculature.
Consider that one common complaint of those who make the transition to minimalist shoes is ‘calf pain’. This is due to the activation of the calf muscles in efforts to slow the heel from striking the ground. They are contracting eccentrically to ‘slow’ pronation. This does not need to be scientifically demonstrated in future studies, as we already know that if pronation of the foot is dorsiflexion, eversion and abduction, then these muscles collectively are contracting as they are lengthening in order to ‘slow’ pronation. As they become strong enough, they will control the pronation that occurs during foot strike (31 and 32).
Examining the categories of traditional running shoes reveals that manufacturers have created them according to three foot types: flat foot, normal arch, and high arch. The American Academy of Podiatric Sports Medicine (AAPSM) has defined the categories as maximum stability, stability, and neutral. For example, ASICS defines its stability category shoe as “structured cushioning” (33). According to ASICS, “the structured cushioning segment is designed for runners who pronate slightly more than normal and generally have a normal arch” (33). This infers that the runner is heel-striking. Otherwise, why would there be a need to control motion? Some of the normal pronation that is encountered when a runner forefoot or midfoot strikes could be inhibited by this motion-controlling apparatus.
Why then are running shoes created with a thick cushioned heel and motion control support? That question is debatable, but it is clear that as running shoes have evolved over the past 40 years, we have seen no reduction in injury rates and marathon times have remained largely unchanged. Many physicians still abide by the rule of changing your shoes every 300 to 500 miles. This became popular after a 1984 study that demonstrated shock absorption loss after 250 to 500 miles of running (34). Since then, studies have demonstrated that as absorptive qualities of a shoe are lost, the foot becomes more stable, leading to the likelihood of reduced injury with greater mileage (35, 36 and 37).
At the same time, a notion that runners “need a great deal of shock attenuation because they don’t absorb shock naturally through pronation” implies that we need to pronate to absorb shock. It becomes extremely crucial to look at pronation in terms of the entire foot, as opposed to only the subtalar joint, because more shock attenuation can be achieved using the forefoot and midfoot.
Even if we consider implementing an orthotic into the shoe to control pronation, we have to consider the purpose of doing this. The orthotic for an overpronator is typically designed to control motion at the subtalar joint that results in the increased pronation. With forefoot striking, we have to look at this from an entirely different perspective, in which the orthotic would not serve the same purpose; therefore, its use is of question.
Where the foot strikes in relation to the rest of the body is also crucial. To increase efficiency and reduce shock to the lower extremity, the foot should be landing under the body’s centre of gravity, or close to it. This engages the body’s natural spring mechanism by using eccentric contractions of the muscles at the ankle, knee, and hip, during landing. In contrast, heel striking, with the leg reaching in front of the body’s centre of gravity, results in the leg impacting in an extended position, increasing the force to these joints. Even if one heel strikes with the foot below the centre of gravity, you will lose part of the spring as the reduction of direct force by its conversion to rotational force through the ankle is lost.
Cadence is another piece of the puzzle. Cadence is the number of steps a runner takes per minute. Examining elite runners and marathoners has determined that achieving a cadenceof 180 steps per minute or higher will result in increased efficiency (38). Running with a forefoot strike pattern makes it easier for one to increase the cadence (23). This high cadence keeps the runner closer to the ground, reducing the vertical motion associated with increased impact forces (23). Shorter strides are associated with a higher cadence, but as speed increases, the stride length will also increase (23, 27 and 32). It is important to understand that cadence should not vary with speed. For example, if running a 10-minute mile or slower, your cadence should remain at 180 or above. Faster paces, such as five to six minutes per mile, can sometimes reach cadences of 200 or above. The key is to understand shorter strides; faster turnover will increase efficiency and reduce ground reactive forces.
Finally, the body’s overall posture also needs to be assessed. This can be somewhat confusing, because some running instructors advise maintaining an upright posture, while others advise leaning forward. Both are actually correct. The body’s overall position should be erect, but it should be falling forward. ‘Leaning’ should not occur at the waist, as it does in bending over, but the entire body should be angled forward. Running in place and then leaning forward to begin movement will help to teach this concept. This increases efficiency by using forward momentum, as opposed to decelerating with each step, which recruits greater musculature.
Focusing on the matters discussed will help to improve a runner’s efficiency, leading to reduced injury. New Balance has partnered with Kurt Munson, a well-known running shoe retailer from Michigan, to create the educational concept known as Good Form Running (18), which teaches these steps in a simplistic manner. Speciality running shoe stores across the United States are holding clinics to teach this method.
Interestingly, children tend to run this way when they are unshod and playing outside (39, 40 and 41). The younger they are, the more noticeable this is, as their gait has not been altered by wearing shoe gear. As for paediatric shoes, the American Academy of Pediatrics recommends not wearing shoes until it is required by the environment (42). This helps to encourage natural foot motion, thereby enabling adequate development and strength gains.
A final point it is crucial to mention is training patterns. Most recreational runners and even elite runners tend to train too hard (17). Improving the body’s aerobic capacity means continuously training at an aerobic rate (ibid). This is best achieved through the use of a heart rate monitor. Training too much at too high a heart rate can lead to overuse injuries (ibid). Runners too often focus on maintaining a pace instead of listening to their body and their training becomes borderline anaerobic (ibid).
Obviously, there is more to running than has been discussed here, but having this as a foundation really helps anyone just starting to run, or even those who have been running for many years. It is crucial for physicians treating running injuries to understand this.
In conclusion, it seems that most practitioners are straying from the path of helping a runner by focusing on shoes, as opposed to form. The term ‘appropriate shoe’ is a misnomer when viewed through the old paradigm of selecting a shoe according to arch type, yet many still advocate choosing shoes this way. Running should allow the foot to function as it was designed to: naturally, without inhibiting motion. Adding cushioned heels and motion control mechanisms can inhibit this.
By viewing shoes as the first line of treatment for most conditions, we must make sure they do not interfere with the foot’s natural function. The shoe should feel comfortable initially (not with time), without a need for the foot to ‘get used to the pressure pushing against the arch’. A gradual adaptation to this way of running is obviously needed, or injury can result, as our feet and bodies may have been accustomed to a different form and supportive shoe. The approach is very similar to creating a programme for someone just beginning to run, although more gradual.
MINIMALIST FOOTWEAR IS NEITHER A FAD
NOR A GIMMICK.
Think about sports specificity. We train in a heavy cushioned shoe with an elevated heel that puts our body in an abnormal position; then, when it comes time to race, we remove
it. There’s not much logic behind that. As athletic trainers, we always put our athletes through a battery of tests to make sure they are ready for competition. These involve activity done the way it would be performed in the event. The logic behind not strengthening
the foot by ‘casting’ it with a motion control shoe and heel striking makes no sense.
As for the surge in injuries that practitioners are claiming to see from runners wearing minimalist shoes, it’s due to the training regimen and form. Shoes do not directly create injury. As for overweight people, or those with poor biomechanics using them, being overweight and heel striking certainly is illogical when compared to reducing shock by forefoot striking and obtaining proper form. The same is true for those with poor biomechanics. Remember we have to redefine ‘poor biomechanics’, because when you forefoot strike, what we learned from Root in terms of overpronation no longer applies.
Shoes with a heel lift for plantar fasciitis work against the stretching that has been advocated in increasing ROM at the ankle joint. Consider that by placing a patient in a 14mm-drop shoe, we actually induce an equinus deformity and then tell the patient to function in it all day.
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