No Glass Slipper for Runners

Cushion, stability, and motion control: three kinds of running shoes for three different foot shapes, according to shoe companies and running magazines. Just pick the right one, they say, and you’ll reduce your risk of injury. Or maybe not. New research suggests that selecting running shoes based on this rule of thumb will do almost nothing to prevent injuries.

The rationale behind this shoe-prescription approach — which has been touted by footwear companies, running magazines and athletic shoe stores — is that the shapes of runners’ feet affect their running mechanics in different ways, and specific shoe types will compensate for those differences, thereby decreasing injury risk. Cushioned shoes are supposedly better for people with high arches, stability shoes for normal arches, and motion control shoes for low arches.

But a recent U.S. Army study of Marine recruits found that those who wore the shoes supposedly appropriate for their foot shape suffered just as many injuries as those in another group, who all wore stability shoes.

When it comes to preventing injuries, this three-pronged approach is based on “an assessment of the foot that basically doesn’t work,” says Dr. Bruce Jones, a co-author of the study and head of the injury prevention program at the U.S. Army Public Health Command in Aberdeen Proving Ground, Md.

The findings, published in the September issue of The American Journal of Sports Medicine, are consistent with a recent study by Michael Ryan, an exercise scientist at the University of Wisconsin, Madison. Ryan’s study of female runners, published online in June in the British Journal of Sports Medicine, similarly found that assigning shoes based on the current conventions did not prevent injuries. He says the focus on shoe type (as opposed to other, less-advertised factors like toe spring or heel height) is misleading, because “what the footwear industries don’t advertise … can have just as much impact on injuries.”

In fact, the real question may not be what kind of shoe, but how much shoe. Daniel Lieberman, a professor at Harvard University who uses barefoot runners to study the evolution of running, says that less may be better. “I advocate a minimal running style,” he says.

Lieberman questions whether modern day running shoes (which didn’t exist before the 1970s) are even healthy to begin with. He has found that runners wearing shoes tend to land heel-first, generating very high collision forces. Without shoes, runners tend to land on the front of their feet, which reduces that force.

Lieberman says that we simply don’t have enough data to determine whether shoes provide the key to injury prevention. “Right now it’s a black box,” he says.

Recent studies do provide some insights, but “if anything, they illustrate that when someone goes to buy shoes, they shouldn’t rely on the salesperson’s judgment,” says Ryan. Until more is understood about the complex relationship between shoes and injury risk, he advises runners to buy shoes that feel comfortable and just “listen to their own body.”