“The Barefoot Professor”, a behind-the-scenes look at the new Nature paper.
Humans that had to escape from saber-toothed cats, giant hyenas, and charging mammoths did not wear Nike or Adidas sneakers. They ran barefoot, but don’t feel too bad that they did not have good running shoes to help them. As suggested by a team of researchers led by Daniel Lieberman in the latest issue of Nature, habitually shoeless runners have a unique step that may be better for our feet than even the most expensive, cushioned running shoe.
Whenever I go for a jog I run in the way that is most familiar to me. When my foot comes down to the ground I lead with my heel, after which my entire foot contacts the ground before the push off launched by the front of my foot. I do not think about it: it is just what comes naturally, and it is what many other joggers who wear sneakers do. But there are two other types of running steps. In a mid-foot-strike runners land with their feet almost flat on the ground, and in a fore-foot-strike the “ball” of the foot (where the toes meet the rest of the foot) hits the ground first.
A comparison of the vertical ground reaction forces and foot kinematics in the same runner using heel-strike (top) and front-foot-strike (bottom) techniques. Note the spike in the reaction force in the top illustration, marking the jarring effect of the heel hitting the ground.
It might be in my best interest to switch to one of these latter running styles. When Lieberman and his team looked at the way several different groups of people ran (including shod US athletes, shod runners from Kenya who started out running barefoot, US runners that switched from wearing sneakers to going barefoot, adolescents from Kenya that wore shoes, and another group of Kenyan adolescents that have never worn shoes) the differences between how shoes affect running became starkly apparent. Runners that had grown up wearing shoes struck the ground with their heel first, even when running shoeless, while those that had started running shoeless preferred the front-foot-strike. And, despite being barefoot, the runners who used the front-foot strike technique experienced less stress on their feet and legs than runners with thickly-cushioned shoes. It is less jarring to run barefoot using the front-foot-strike than to run in heel-strike fashion with even the best running shoes.
What this study suggests is that the front-foot-strike might be the most natural foot posture during running and therefore may be the way early members of our species ran long before the invention of shoes. In fact, our modern shoes might be encouraging us to run in a manner inconsistent with the way our feet were adapted, hence causing more injuries than would otherwise occur. Despite all the money that has been poured into reducing stress injuries caused by running by creating better shoes, the best way to reduce running injuries may be to simply toss the shoes and alter our foot posture. As the authors admit, more research is required to determine whether this is true, but if their hypothesis is correct then we would do better to run like our ancestors did.
Lieberman, D., Venkadesan, M., Werbel, W., Daoud, A., D’Andrea, S., Davis, I., Mang’Eni, R., & Pitsiladis, Y. (2010). Foot strike patterns and collision forces in habitually barefoot versus shod runners Nature, 463 (7280), 531-535 DOI: 10.1038/nature08723