Since the publication of Born To Run by Chris McDougall, the interest in barefoot (or minimalist) running has exploded. For example, check out the attached google trends map for a visual on the number of hits associated with the topic over the past few years.
It’s not uncommon these days to be on the starting line of a race, look down, and see a smattering of Vibram-clad feet surrounding your trusty old Nikes. For many runners who have struggled with a lifetime of injuries and the frustrations associated with their inability to train consistently, barefoot running seems a viable alternative to utilizing physical therapy , orthotics or heavier motion-control shoes.
Much of the research surrounding the utility of barefoot or minimalist running has come from one of two areas: observational studies of runners in certain geographic regions who spend long periods of time training barefoot, and laboratory biomechanics tests on barefoot vs shod runners to look at differences in gait patterns. Let me give you some examples. Runners from the Kalenjin tribe in Kenya, who typically grow up running barefoot, almost uniformly strike with the forefoot or the midfoot rather than the heel. Notably, some of the best marathoners in the world have emerged from this tribe. Moreover, Dr. Dan Lieberman, of Harvard University’s Skeletal Biology Laboratory, has examined the force associated with barefoot and shod running, showing that forefoot striking generates dramatically less force than heel striking since heel striking generates a substantial impact force when the heel collides with the ground. Cumulatively, these data suggest that modern shoes, with all their cushioning and padding in the heel designed to “cushion” heel impacts, could actually increase injury by shifting our “natural” footstrike from the forefoot to the heel.
Unfortunately, though, the story is not so simple. While it is true that certain runners thrive running barefoot or in minimalist shoes, others develop injuries almost immediately. For example, clinicians have reported increasing injuries produced by barefoot running. Several recent studies have shown that switching to barefoot running and/or forefoot striking increases back stress and bone marrow edema, a marker of foot stress. In addition, observations of a different Kenyan tribe– the Daasanach— show that despite a lifetime of barefoot running, the majority strike with their heel rather than their forefoot, casting doubt on the theory that heel striking is a new, maladaptive biomechanics pattern associated with wearing modern running shoes. And finally, studies in elite runners find huge heterogenity in their biomechanics, with no performance benefit of forefoot over heel striking (click here for a great video of the foot strikes among elite runners in the 2012 US Olympic Trials Men’s 10K).
So, at the end of the day, while we are all born to run, we probably aren’t all born to run barefoot…and that may not be a bad thing.