You can hear some runners coming from a mile away thanks to the force with which they stomp the pavement. Not only does this impact sound painful, but new research suggests it could be doing real damage.
A study out of Harvard Medical School looked at the impact loading of runners—how hard they pounded the ground with each step—and how it related to injuries. Over two years, just 21 of the 249 runners reported no injuries in that window of time, nor had they experienced injuries before. When the researchers controlled for factors such as mileage and weight, they discovered that the uninjured few were a lot lighter on their feet than those with medically diagnosed injuries.
If you are one of those heavy pavement pounders, it may be worth considering one of these approaches to reduce impact loading.
Get real-time feedback. Research has shown that real-time visual feedback can help reduce the rate of impact loading for runners. Doing a workout on a treadmill with a mirror nearby can be a great way to get this type of visual feedback while on the run. “This is effective to correct faulty running mechanics such as excessive vertical displacement [bounding too high], dynamic knee valgus [knees collapsing inward], pelvic drop [one hip angling downward], and [arm] cross-over,” explains Colleen Brough, a physical therapist and director of Columbia RunLab in New York City.
Verbalize it. Brough says that verbal cues such as “land more quietly” or “increase forward lean” can help you tune into—and modify—how hard you’re coming down with each step. If you need some guidance with crafting your custom cues, a physical therapist or coach can help.
Increase cadence. Research published in the American College of Sports Medicine’s journal showed that increasing step rate can help reduce the loading on the hip and knee joints during running. “The study demonstrates a reduction in foot and knee impact by increasing your ‘preferred’ cadence by 5 percent, which means that even if your cadence is 160 steps per minute and you increase by 5 percent to 168 steps per minute, you decrease impact forces at the foot, ankle and knee,” explains Brough. “If a runner can increase by 10 percent, reduction in forces are observed at the hip, which is very exciting from a rehab perspective.”
Pay attention to landing. While there is much debate over whether forefoot, midfoot or heel striking is better, when it comes to impact force, Brough says what really matters is where the foot lands in relation to the runner’s center of mass and the degree of knee flexion at landing. “A straighter, locked knee doesn’t have much give and increases impact forces,” she says, so ideally, you should land almost directly under your center of mass to eliminate the braking motion that occurs when you strike the ground while leaning too far forward. Proper forward lean and increased cadence can both assist in this department. Consider recruiting the help of a gait analysis expert to zero in on changes that will help you lighten your strike load.