Perhaps the original design is still the best. In this week’s Nature, Harvard’s Daniel Lieberman and his team reported on the impact force of people who are used to running barefoot versus those of us who wear spongy sneakers to protect the bottoms of our feet. Those who ran barefoot (the way humans evolved to run) moved differently, and with far less stress on their feet than the shoe-wearing masses.
The researchers first traveled to Kenya to watch endurance runners who grew up running sans shoes. The study—the first to test lifelong barefoot runners and not simply people trying it out—found that the barefoot runners landed on the front or middle of their feet. By contrast, runners in shoes typically land on their heels. Lieberman says: “This creates an impact; it’s like someone hitting your heel with a hammer with up to three times your body weight” [BBC News]. In follow-up tests in the United States, the team noted that barefoot runners put, on average, only a third of the initial impact force on their feet than their shod counterparts did.