Knee pain and its relationship to the hips
Patellofemoral pain (PFP) is one of the most common running injuries. It can be defined as pain along the front of the knee and in and around the knee cap. PFP may occur when the kneecap (patella) and thighbone (femur) abnormally/excessively rub against each other. Runners suffering from PFP generally don’t feel pain when they begin running, but once the pain starts, it gets increasingly worse, then often vanishes almost immediately after running ceases. Studies show that PFP may actually prematurely wear away cartilage behind the kneecap and in the thighbone, having a similar effect as osteoarthritis. It has been suggested that exercises that strengthen the hip may in fact alleviate PFP, since stronger hips may correct running form errors that contribute to PFP. To test whether or not the theory held true, Tracy Dierks, an assistant professor in the Department of Physical Therapy at IUPUI, conducted a study on female runners and found extremely positive results.
Six-week program for nine runners
The study group was comprised of nine female runners that showed many of the classic signs of PFP, the most prominent being the knees collapsing inward while running or performing squats. Five runners underwent the intervention and the other four comprised the control group. Hip strength measurements and pain assessment scores on a scale from 1-10 were taken before and after the intervention, which lasted six weeks. The training regimen for the intervention group consisted of two exercise sessions (30-45 minutes long) per week, which involved single-leg squats and exercises with a resistance band, all of which can be performed at home. The control group simply continued their normal running schedule for the six-week trial period.
Incredibly positive outcomes
Injured runners in the intervention group began the trial reporting pain while running at level 7, or very strong pain, and finished the study period reporting pain levels of 2 or lower, which registers as no onset of pain. Even the study’s creator, Dierks, was shocked by the results: “I wasn’t expecting such huge reductions, to be honest…We’ve had a couple of runners who have been at level 2, but the overwhelming majority have been a 2 or below.” Dierks claims this is the first study of its kind and now plans to seek funding to test these findings on a much larger group of runners to further confirm that hip-strengthening exercises can have a major impact on alleviating knee pain.