on October 22nd, 2014 1 Comment
It may surprise you to learn that past studies show that runners have a 50 percent chance of sustaining an injury that disrupts their training, and those that compete in marathons have an incidence rate as high as 90 percent. But don’t hang up your sneakers just yet. Many common aches and pains that nag runners can easily be treated or avoided.
On Thursday, Michael Fredericson, MD, who is director of the Stanford Runner’s Injury Clinic and has been head team physician with the Stanford Sports Medicine Program since 1992, will talk about the latest running prevention and treatment methods during a Stanford Health Library lecture. (For those unable to attend the event in person, you can watch the live webcast starting at 7 PM Pacifiic time.) To kick off the conversation, I reached out to Fredericson to discuss some of the topics of his upcoming talk, including the harms of overstriding, the benefits of cross-training, and remedies for prevalent joint problems. He and Adam Tenforde, MD, a sports medicine fellow at Stanford, responded to my questions.
How can overstriding lead to injury?
The term “overstriding” refers to running with the foot striking the ground too far forward from normal stride length. This results in heel strike pattern that may increase stress in the hip and knee joints. Research has shown that forefoot strike patterns tend to reduce stress on the knees and hips, although this may lead to greater stress on the foot and ankle. We conduct a clinic called RunSafe, where we evaluate gait of runners using video and markers. More efficient stride frequency is 90 strides per leg per minute. When a runner overstrides, this may result in a lower stride rate and an inefficient gait. We evaluate for the causes of overstriding, including poor hip extensor strength (weak gluteal muscles), decreased flexibility and technique and encourage correction of these biomechanical contributors. Also, we may suggest shoes with reduced weight, such as ‘minimalist shoes’ as these tend to encourage a runner to run with a more mid-foot strike pattern. However, we caution any changes in shoe type or technique be introduced gradually to decrease risk of developing an injury from changes in gait pattern that stress the body in a new way.
Why is it important for runners to cross-train?
Cross-training refers to forms of aerobic exercise that do not involve running. Doing exercises that do not involve the repetitive ground-impact experienced during running help to rest tired muscles and decrease stress on bones, assisting in recovery while building aerobic capacity. There are no established forms of cross-training to prevent injuries, but performing exercises that do not involve impact loading through the legs, such as elliptical trainer, cycling or deep water running may be helpful.
Many runners select shoes that compensate for how their foot pronates. But recent research shows that pronating too much or too little may not actually increase a runner’s risk of injury. How important is pronation and foot type in preventing injuries?
We evaluate foot type and pronation during our RunSafe clinics. Pronation is a normal motion that helps to distribute forces while landing through the foot and ankle, reducing stresses through the lower extremities. If the foot abruptly stops moving from too much or too little pronation, the other joints and lower limbs may absorb these forces and can become injured. Foot type (having too high an arch or too flat a foot) may also result in higher forces in the legs and joints through associated biomechanics. Foot type and concerns of pronation need to be put into context of prior injury history, as recent research has suggested that foot type and pronation do not necessarily predict future injury risk.