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Runners: Stop the Pronation Panic


If you walk into a sporting goods store and ask for shoes, you're likely to be thrown on a treadmill and have your strides dissected on video as if you were crossing an Olympic finish line. Salespeople will give you a thorough analysis of your gait. They may break the news that you "over-pronate," rolling your foot inward to some degree at the end of each step. Don't worry! It's common—and they sell a shoe made for your specific flaw. It's all very scientific, except that it isn't.

Rasmus Nielsen, a sport science graduate student at Aarhus University in Denmark, has seen the process from both sides of the in-store treadmill. When he first started running, he was told he should buy motion-control shoes to correct his pronation. Five years later, he started working in a running store.

"I was told to advise individuals to buy stability or motion control shoes if they were pronators," Nielsen says. "I started to ask the question, 'Why do we do this?' No evidence-based answer was provided."

Since becoming a physical therapist and seeing thousands of runners in his clinic—and dealing with his own running injury—Nielsen has developed a new perspective about where injuries come from. He doesn't think pronation or supportive shoes matter much at all. To add some evidence to the discussion, he conducted a study of more than 900 novice runners.

The subjects were healthy Danes of various ages and sizes—on average, 37 years old with a BMI of 26—who didn't run before the study. Physical therapists assessed their gaits and scored each person's feet as neutral, moderately or highly pronated, or moderately or highly supinated (rolling outward). Then subjects spent the next year running as much as they wanted. They logged their miles with a GPS watch and called the study leaders for an appointment if any injury cropped up.

Whatever their gait, all subjects were given identical "neutral" running shoes. Nielsen reasoned that if matching running shoes to foot type prevents injuries, then people with pronating or supinating feet should injure themselves sooner in these shoes than people with neutral feet.

That didn't happen.

Injuries were common; more than a quarter of the new runners were sidelined by injury at some point. But people's foot types had no relation to how soon they got injured. In fact, pronators had slightly (but significantly) fewer injuries per thousand kilometers run than neutral runners did.

Nielsen isn't the first researcher to find plot holes in the story told by shoe companies. A 2009 review concluded that there was no evidence behind the way different shoe types are prescribed. In 2011, a study of female runners found that those randomly assigned to wear motion-control shoes experienced more injuries than those assigned to other types of shoes.

Since the current study only involved uninjured, novice runners, the authors point out that motion-control shoes could be helpful to people who've already had an injury. It's also possible that the most extreme pronators are more prone to injury; in the study, this group was so small—only 18 people—that no real conclusions could be drawn about them. Yet for garden-variety pronators, there was clearly no extra injury risk.

These days, Nielsen says he can run in any type of shoe, once he gets used to it. He thinks how people train matters much more for their injury risk. Worrying about your sneakers, he says, isn't worth it. "I would definitely advise other runners [to do] otherwise than I did."


Image: by Danielle Walquist Lynch (via Flickr)

Nielsen, R., Buist, I., Parner, E., Nohr, E., Sorensen, H., Lind, M., & Rasmussen, S. (2013). Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study British Journal of Sports Medicine DOI: 10.1136/bjsports-2013-092202

6 comments:

  1. one sign says it all...$

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  2. once again, you're asking the wrong questions and getting terrible conclusions from bad data. Why are you looking at the shape of the foot for the degree of pronation? You can have overpronation both from an inflexible arch and a hypermobile navicular bone, both of which will over-rotate the knee prior to the hip loading up with weight, but the answer will be different for both when it comes to realigning the leg. Its way more complex than is being described here, so to present such data as being conclusive is spurious.

    "In 2011, a study of female runners found that those randomly assigned to wear motion-control shoes experienced more injuries than those assigned to other types of shoes." And this is absurd also. There is no meaningful data here what so ever. To randomly assign a specific style of shoe onto a number of feet, when we have no idea what they should actually be using, is to gain no meaningful assessment of the efficacy of the shoe's abilites, or whether it could even potentially be helpful whatsoever. It makes zero sense.

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    Replies
    1. What is spurious is the fact that numerous studies link under or overpronation (measured in the same way, through gait analysis) to plantar fascitis and a large number of conditions. You can't have it both ways. Sure sure, I agree it is more complex, but you to incorporate seemingly contradictory information in a novel way. And you cannot do that through simplistic ideas of pronation but instead must actually measure the forced being exerted on the foot. Why isn't this done?!

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    2. By the way, I mean forced exerted on the foot for plantar fasciitis. There is no doubt weight is a factor, as is age and so on. But why do some people develop it while others do not, yet have all the risk factors? I have plantar fasciitis now and also as a teen but it lasted only 1 month. Then I ran on hard surfaces in soccer shoes for about (no exaggeration here) 10 hours per week. Then I stopped exercising, and gosh-darn it, at 21 my foot began to hurt again. I think clinicians are real assholes when they point out a change in activities caused my problem. I didn't come in to talk about something as obvious as that anymore than a doctor should get paid to say eat right and exercise.

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    3. To be utterly clear, I mean to say that I had foot problems as a teen for a month, then recovered and was fine. There is no reason to believe my gait changed in a one month period, nor my foot either. Anyway, pronation as the cause of 'instability' or 'imbalance' is as nonsensical as the chiropractors adjusting spines. If you are so smart than fix the fucking problem. (Oh, its more complex than that!) Fuck you. If you know whats wrong than fix it, don't critique and analyze. If you don't understand, by all means, go back to doing research.

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  3. Barefoot runners apparently don't have this problem at all.

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