Running Insight

4 runninginsight.com © 2017 Formula4media LLC. a large impact on the runner and the running stride. Which is why, besides the influence of marketing, the myths persist. The question of what shoes can and cannot do and how to find the right ones for you could be the topic of its own book. Here, let's look briefly at what we seem to know now and what is important to pay attention to if you're working to improve your stride. Pervasive Pronationism The driving idea at the center of shoe design and prescription for most of running shoe history has been the belief that overpronation—the foot rotating too far inward—is a sign of a poor stride, a cause of injury, and something the shoe should protect against. The pervasiveness of this idea has culminated in what Bartold calls "pronation-ism." A runner goes to a shoe store or podiatrist and comes home devastated. "Oh my god, I've just been told I'm an overpronator and my world has ended," Bartold jokes—a joke with a bite because it is so close to the truth. I've encountered runners, from ages 12 to 70, who have been told they need motion control and consider it a diagnosis, a lifetime sentence to wearing heavy, stiff, controlling shoes. Despite this persistent emphasis, neither science nor experience has confirmed the connection between pronation and injury. "I think pronation has been given a very bad rap," Bartold says. "It is just a movement, and it is a normal movement, and it is a very essential movement." Everyone pronates. Some pronate more than others. We can measure the angle of pronation, Bartold explains, but we don't know how much is too much. "We've had this suggestion that somehow we were able to identify what was overpronation," Bartold says. The truth is that some people pronate quite heavily without any ill effects. "Everybody has an envelope of function— we all work in that envelope. For some people it is very narrow; for some, it is wide." Benno Nigg, one of the world's most respected biomechanics researchers, now retired, agrees, despite most of a lifetime trying to prove otherwise. "When I got into the field, there was never a question that pronation was a major thing," Nigg says. "The only thing I wanted to do was provide proof that it was a bad thing." Over 50 years of studying shoes and runners, however, he failed to find the direct connection between pronation and injury. "The injuries didn't reduce over the 50 years," Nigg says. "The instances [were] about the same." In a 2015 article in the British Journal of Sports Medicine, Nigg wrote, "It is difficult to find supporting evidence that foot pronation (eversion) is a strong predictor of injury." He wrote, in his 2010 book, Biomechanics of Sports Shoes, "Pronation is a natural movement of the foot and 'excessive pronation' is a very rare phenomenon. Shoe developers, shoe stores, and medical centers should not be too concerned about 'pronation' and 'overpronation.'" The first danger comes when runners are put in a heavy, stiff motion-control shoe just because of the extent of their pronation, without concern for whether or not that pronation is stressful to their system. Experts agree that the majority of people do not need the level of support they've been wearing. "Everyone should be in cushion neutral or below," says podiatrist Rob Conenello. Bartold estimates that serious motion-control shoes are necessary for no more than 1 in 1,000 runners. "Most runners simply don't need that kind of stability," he says. Martyn Shorten, head of the research lab BioMechanica, estimates that only 10 percent of runners need any kind of stability in their shoe at all. Shoes Can't Correct You Not only do we not know what level of pronation requires support, but the methods typically used to try to control motion are suspect. "You can't control motion," Bartold states. "Science tells us that you can put all this stuff in a shoe and make it very stiff, with motion control, and if you have a foot that pronates, it will pronate very nicely inside that shoe. The whole concept that you can build a shoe that is going to control pronation is fatally flawed." Once again, Nigg agrees. "The degree to which a change in shoe construction can affect total foot or ankle joint eversion [inward twisting] is small and not relevant," he says. Nigg goes on to say that these "control" devices are not only ineffective but counterproductive. He returns to the idea that each person's body finds a preferred The Myth of the Magic Shoes (continued) "I think pronation has been given a very bad rap, It is just a movement, and it is a normal movement, and it is a very essential movement." Simon Bartold Podiatrist, Biomechanics Researcher "Pronation is a natural movement of the foot and excessive pronation is a very rare phenomenon." Benno Nigg Biomechanics Researcher "Everyone should be in cushion neutral or below." Rob Conenello, Podiatrist

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