a popular myth about running injuries: pronation unmasked

Today’s NYTimes Well blog featured a story near and dear to the hearts of many of our runner patients, namely, how much pronation is right, and if you have too much or too little, are you likely to be injured?

Some background: pronation is an often misapplied term. In its strictest sense, it is used to describe motion about an oblique axis in the foot, namely the subtalar joint. It has been expanded from that use to include a general description of “flattening” of the foot, a combination of three motion patterns, eversion, external rotation, and plantarflexion.

Recently, it has been described by a noted orthopedic surgeon, Dr. Sig Hansen of Seattle as dorsal lateral peritalar subluxation, anatomically distinguishing the foot from the ankle.

What we know definitively is that the soft tissue envelope around the leg, heel, and ankle is misleading. Consensus observation of hindfoot alignment has not been shown to match radiographic alignment, necessitating the use of either Kirby or Saltzmann views to understand the position of the heel to the leg.

What this all boils down to  in the context of the study is, how much adjustment can the foot go through while running without being injured. From the article:

“For the new study, published online this month in The British Journal of Sports Medicine, researchers from Aarhus University in Denmark and other institutions began by advertising in Danish newspapers and at gyms to find men and women who didn’t run but were game to try.

Contrary to received running wisdom, however, those who overpronated or underpronated were not significantly more likely to get hurt than runners with neutral foot motion.This result confirms those of several earlier experiments showing that when runners choose their shoes based on their foot type — when overpronators wear motion-control shoes, for instance, to reduce how much they pronate — they sustain injuries at the same rate or at higher rates than when they choose shoes at random.

In essence, what these findings suggest, says Rasmus Ostergaard Nielsen, a doctoral researcher at Aarhus University who led the new study, is that supposedly deviant degrees of pronation may not in practice be abnormal and do not contribute to injuries.

And if that is the case, he continues, runners, especially those new to the activity, probably do not need to obsess about their foot type. Instead, he says, they could more profitably “pay attention to things like body mass, training, behavior, age and previous injury in order to prevent running-related injuries.”

Other researchers agree. “This is an excellent study,” says Bryan Heiderscheit, an associate professor of biomechanics and director of the running clinic at the University of Wisconsin at Madison.

The research reinforces a widespread belief among scientists studying running “that pronation doesn’t play much of a role” in injury risk, he says. It also suggests, he says, that trying to alter pronation with a specific type of shoe is probably misguided.

At the university’s running clinic, “we see so many injured runners who’ve been told that they overpronate” and need sturdy motion-control shoes to fix the problem. “They wind up injured anyway.” Instead, he says, this new study and common sense suggest that comfort is likely to be a better guide to shoe choice than foot posture. “We don’t know” whether anyone’s given degree of pronation needs to be altered, he says. “We do know that comfort helps” to make running tolerable. But when he asks injured runners at the clinic whether their current shoes are comfortable, “it’s amazing,” he says, “how many say no.”