Matt Fitzgerald provides a few adjustments you can make to your running stride to reduce your risk for injury.
Some runners hit the ground hard with their feet. Others land softly. Even when two major factors affecting impact forces—body weight and running speed—are held constant, there is a large degree of individual variation with respect to ground impact. Certain subtleties in biomechanics appear to be at fault for causing a hard landing in some runners.
You can’t always identify a stomper by watching them run. But you can tell from their injury history. Studies have shown that runners exhibiting unusually high impact forces when they run also have a very high risk of developing common overuse injuries such as plantar fasciitis and shin splints.
The good news is that there are also studies showing that runners can learn to run more softly. For example, in a 2010 study, Irene Davis of the University of Delaware used visual biofeedback to train a group of 10 stomping runners to run with less impact. A one-month follow-up test revealed that the change was permanent.
According to Davis, you don’t need high-tech force plates and visual biofeedback monitors to learn to run with less impact. “Practice running at a higher cadence, or more strides per minute, without changing your pace,” she says. For example, if your left foot normally lands 75 times per minute, aim for a 10 percent increase, or 82 to 83 strides per minute. This will naturally shorten your stride and make your feet land flatter, which is less jarring than an overstriding heel strike.
Don’t try this unless you are often injured, however. That’s because any change you make to your natural stride will make it less efficient, even if it does lower your injury risk.
I’m living proof. A couple of months ago I switched to a softer stride that allowed me to run without pain in my left Achilles tendon, which I could not do with my natural stride. Then I visited the biomechanics lab of Stephen McGregor at Eastern Michigan University. McGregor had me run on a treadmill alternately with my new (softer) stride and my old (harder) stride. Then he showed me some graphs. Sure enough, the new stride reduced my measured impact force considerably. But it also reduced my running economy.
McGregor cheered me up. “The fastest way to run is not always the best way to run from an optimal performance standpoint,” he said. “With the improved fitness you may accumulate as a result of staying healthier, you could end up running as fast or faster than before.”
And so might you.