People who regularly run barefoot, or run wearing minimal footwear, hit the ground differently with their feet, according to new research from Harvard University.
In doing so, these runners lessen the impact on their bodies.
“People who don’t wear shoes when they run have an astonishingly different strike,” said Daniel E. Lieberman, professor of human evolutionary biology at Harvard University and co-author of a paper on the subject. “By landing on the middle or front of the foot, barefoot runners have almost no impact collision, much less than most shod runners generate when they heel-strike.”
Runners with shoes on tend to strike the ground with their heels, leading to an impact equivalent to two to three times their body weight, Lieberman said.
Lieberman, along with co-researcher Madhusudhan Venkadesan, also from Harvard, analyzed the running gaits of shod and unshod people in the U.S. and Kenya.
Lieberman chose Kenya, he said, because the region holds 50 per cent of the world records in endurance running and also has many barefoot runners.
“So we could compare people who run a lot and had grown up wearing shoes (and compare it to those who had) grown up barefoot,” he said.
In Kenya, they captured footage of people running on the ground with a high-speed video camera.
In the U.S., they measured the force of the impact by having people run on scales embedded in the ground. They also used a 3-D motion analysis system.
“Heel-striking is painful when barefoot or in minimal shoes because it causes a large collisional force each time a foot lands on the ground,” said Venkadesan, in a news release. “Barefoot runners point their toes more at landing, avoiding this collision by decreasing the effective mass of the foot that comes to a sudden stop when you land, and by having a more compliant, or springy, leg.”
Shoes are a relatively new invention and humans’ evolutionary history points to traits the favoured barefoot running, Lieberman said.
In their paper, which will appear this week in the journal Nature, the authors point out that modern running shoes didn’t even show up until the 1970s.
“For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning,” they write.
Lieberman admitted his research might not usher in a resurgence of barefoot culture in North America.
“Shoes are great because they are comfortable, and I don’t think we will ever become a barefoot culture,” he said. “Most runners can and do wear shoes if they can. But I think it’s fun to run barefoot (but) some may prefer to run the way they do in cushioned shoes. I think the key is for people to do what they want, have fun and avoid injury. There is no one way to run.”
Runners looking to make the change to barefoot jogs when they’ve worn shoes their whole lives may find it difficult as their muscles adjust, he said.
“If you’ve been a heel-striker all your life you have to transition slowly to build strength in your calf and foot muscles,” he said.
Nonetheless, barefoot running in North America is a trend that has attracted many shunners of shoes and produced many blogs and books on the topic.
Proponents of the activity advocate ditching shoes completely, claiming they actually cause more damage than they prevent.
Abebe Bikila, an Ethiopian marathon runner, won a gold medal and set an Olympic record when he ran barefoot at the 1960 Olympic Games in Rome.
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