In recent years, many barefoot running enthusiasts have been saying that to reduce impact forces and injury risk, runners should land near the balls of their feet, not on their heels, a running style that has been thought to mimic that of our barefoot forebears and therefore represent the most natural way to run. But a new study of barefoot tribespeople in Kenya upends those ideas and, together with several other new running-related experiments, raises tantalizing questions about just how humans really are meant to move.
For the study, published this month in the journal PLoS One, a group of evolutionary anthropologists turned to the Daasanach, a pastoral tribe living in a remote section of northern Kenya. Unlike some Kenyan tribes, the Daasanach have no tradition of competitive distance running, although they are physically active. They also have no tradition of wearing shoes.
Humans have run barefoot, of course, for millennia, since footwear is quite a recent invention, in evolutionary terms. And modern running shoes, which typically feature well-cushioned heels that are higher than the front of the shoe, are newer still, having been introduced widely in the 1970s.
The thinking behind these shoes design was, in part, that they should reduce injuries. When someone runs in a shoe with a built-up heel, he or she generally hits the ground first with the heel. With so much padding beneath that portion of the foot, the thinking went, pounding would be reduced and, voila, runners wouldnt get hurt.
But, as many researchers and runners have noted, running-related injuries have remained discouragingly common, with more than half of all runners typically being felled each year.
So, some runners and scientists began to speculate a few years ago that maybe modern running shoes are themselves the problem. Their theory was buttressed by an influential study published in 2010 in Nature, in which Harvard scientists examined the running style of some lifelong barefoot runners who also happened to be from Kenya. Those runners were part of the Kalenjin tribe, who have a long and storied history of elite distance running. Some of the fastest marathoners in the world have been Kalenjin, and many of them grew up running without shoes.
Interestingly, when the Harvard scientists had the Kalenjin runners stride over a pressure-sensing pad, they found that, as a group, they almost all struck the ground near the front of their foot. Some were so-called midfoot strikers, meaning that their