(*This is an article I wrote for ChicoTC’s monthly newsletter in 5/2011 and has not been changed/altered to reflect any new research to date)
Although many people are just now hearing about this “new” hot topic known as barefoot running, it is far from a novel idea. Runners of all abilities have been employing this technique for thousands of years. Just in the last five decades names such as, Zola Budd (1985 and 1986 IAAF World Cross Country Champion) and Abebe Bikila (Olympic marathon gold medalist in 1960; He again won gold in 1964 but wore a pair of Puma shoes and ran 3:05 faster!) stand out as a few of the elite runners that engaged this concept.
This latest boom in minimalistic running can be attributed to Christopher McDougall’s book, Born to Run1, which highlights the Tarahumara tribe of Mexico. McDougall claims that these runner’s experience lower injury rates and increased performance simply by running in minimal sandals or going barefoot and uses his own anecdotal claims to support the theory. The author goes on to blame the modern day running shoe as the cause of many running related injuries and advocates for society to move back to a more “natural” way of running.
With a media storm of conflicting claims, what should we as athletes and consumers believe? I hope that this brief article will help answer a few of those questions and give you a better insight at what current research is saying about this debate.
The purported benefits of barefoot running:
1) Reduction in impact forces at ground contact
2) Stronger plantar intrinsic musculature
3) Increased proprioceptive feedback which can lead to a reduction in ankle sprains
4) Improved energy utilization
*All of the purported benefits are said to increase performance while decreasing the risk of injuries.
Evidence supporting said purported benefits of barefoot running:
One of the top referenced studies in the media and in the medical community comes from an article published in the 2010 January issue of Nature, authored by Daniel Lieberman, PhD, and professor of Human Evolutionary Biology at Harvard University. In his study that looked at foot strike patterns, they found that there was a reduction in transient forces throughout the lower leg with forefoot or midfoot striking, when compared to rear-foot striking. This has now been widely used to support the superiority of barefoot running, as a reduction of forces throughout the lower leg from forefoot striking should translate to a reduction in lower leg injuries. However, Dr. Lieberman was quick to state, “Although there are anecdotal reports of reduced injuries in barefoot populations, controlled prospective studies are needed to test the hypothesis that individuals who do not predominately rear-foot strike either barefoot or in minimal footwear, as the foot apparently evolved to do, have reduced injury rates”2 (Worth noting, Vibram USA helped fund this study)
There is limited research that shows a runner may increase the size and strength of their intrinsic musculature, which in turn would increase the strength of their arch structure in the foot.3,4 However, at this time there is no evidence that links this with an increase in performance or reduction of injuries.
Proprioceptive awareness of the surface underneath ones foot has been shown to improve in static (not running) controlled conditions, which should help a person activate musculature that would prevent an inversion ankle sprain.5,6,7 However, at this time there is no evidence that links this to an increase in performance or reduction in injuries.
There is limited evidence to support some barefoot runners are more efficient with energy utilization when compared to shod runners.8,9,10 However, (see where this is going?) at this time there is no evidence that links this with an increase in performance or reduction of injuries.
The purported risks of barefoot running:
1) Surface hazards (i.e. Debris, surface temperature)
2) Achilles and musculotendonious injuries from forefoot striking (tendon and muscular problems)
3) Osseous injuries due to overuse (bone issues)
4) Lack of support for people with pes cavus or pes planus (High arch/low arch)
5) Increased risk of injuries in people with lack of protective sensation in their feet (i.e. diabetes mellitus)
Evidence supporting said purported risks of barefoot running:
Most of us have walked around barefoot and been unfortunate enough to step on something sharp or hot and quickly find ourselves removing the limb from the painful stimulus. Therefore, it would seem like logic and common sense that running barefoot would increase ones exposure to potential hazards such as rocks, glass or even extremely hot manholes and other maintenance coverings’. However, currently, there is no evidence that states barefoot runners are at a higher risk of surface hazards compared to shod runners.
To allow for the lower transient ground reaction forces shown in Dr. Lieberman’s study, the plantar flexors are recruited to a much higher percentage when eccentrically lowering a person’s heel to the floor. Clinically and from a pathophysiology standpoint, this significant amplification in force on the calf musculature would increases the risk of achilles tendonitis, calf strains and even plantar fasciitis if the runner is not strong enough to handle the load. However, to date there is no evidence that links these overuse injuries to barefoot running.
Currently there is no evidence to link stress fractures with barefoot running.
For people that use corrective footwear such as posts, orthotics, motion control or stability shoes, the risks of removing said devices logically would increase a person’s risk of developing further foot ailments. However, no research has been done to link barefoot running with increased injuries in people with biomechanical issues.
For people that lack sensation in their feet (peripheral neuropathies), it is considered a contraindication to attempt barefoot running. The risks of developing foot ulcers, infections and many other conditions is tremendously increased with the inability to feel the beginnings of skin breakdown in the foot.11,12
RATING: Now that we have reviewed the research, do I recommend it? Since this article is intended to represent what the current literature is saying and not to be founded on logic and reason or my own clinical judgment, I am giving barefoot running a neutral thumb. More research is CLEARLY needed as barefoot running has not shown to enhance or inhibit performance, or increase or reduce injury rates. That being said and knowing science often times will lag behind what society supports, as a future health care practitioner I have an obligation of nonmaleficence to my clients and patients and will breakdown my recommendation into three subcategories.
For people who are overweight, out of shape, just beginning the sport, have major biomechanical issues, impaired or absent protective sensation, or those that have successfully run shod with no history of serious injuries that limited performance or participation. I believe that the risk-reward ratio is too high in this group and instead the goal should be to establish a baseline in strength, flexibility, cardiovascular fitness and consistency. Until further research links barefoot running with reduced injury rates or increased performance, I would caution people against the hazards of shifting their gait mechanics that have been in place for 10, 20, 30+ years.
For people looking to supplement their current training with an alternative type of running whom also display good strength and flexibility, a consistent history of training, and are biomechanically sound. This may be an exciting and enjoyable way to break up the daily grind of running and might even strengthen the intrinsic musculature of the foot and lower leg that could potentially help reduce injury rates. HOWEVER, make the transition very slowly to allow your muscles, tendons, bones and ligaments time to adapt to the new stresses and do not completely replace shod running with barefoot running. This will help avoid an almost inevitable increase in plantar fasciitis, achilles tendonitis, plantar flexor strains, and other overuse injuries if the shift is attempted incorrectly.
For people that are currently running barefoot or employ minimalistic types of running. If things are working, nothing is breaking down, and there is no evidence to say otherwise, I believe in continuing along a path that has proved successful in the past.
2. Foot strike patterns and collision forces in habitually barefoot versus shod runners. Lieberman D, Venka desan M, et al. Nature. 463; 531, 2010.
3. The influence of footwear on the prevalence of flat foot. A survey of 2300 children. Rao U, Joseph B. J Bone Joint Surg Br 74-B: 525, 1992.
4. Effect of increased mechanical stimuli on foot muscles functional capacity. Brugemann G, Potthast W, et al. American Society of Biomechanics; 2005:553.
5 . Proprioception and stability: foot position awareness as a function of age and footwear. Robbins S, Waked E, et al. Age Ageing 24: 67, 1995.
6 . Shoe sole thickness and hardness influence balance in older men. Robbins S, Gouw GJ, et al. J Am Geriatr Soc 40:1089, 1992
10. Running economy and kinematic differences among runners with foot shod, with the foot bare, and with the barefoot equaled for weight. Flaherty R. 1994 SPORTDiscus
11. Infected puncture wounds in diabetic and nondiabetic adults. Lavery L, Walker S, et al. Diabetes Care. 1996. 19:549. 1995 18:1588
12. Is walking barefoot a risk factor for diabetic foot disease in developing countries? Jayasinghe S, Atukorala I,
Gunethilleke B, et al. Rural Remote Health. 7: 692, 2007.
13. Advising Your Patients about Barefoot Running: What should you tell patients when they ask? Jenkins D. Podiatry Management. Nov-Dec 2010; 29(9): 59-64