Swimmers have their ears. Tennis players have their elbows. Us runners have our knees.
When you consider the act of running and the impact our bodies absorb each time a foot hits the ground, it’s no wonder our knees are susceptible to injury. There is a variety of things that can go wrong at this joint, but one of the most common knee injuries is patellofemoral pain syndrome, or runner’s knee. This happens when the kneecap slides off its normal track and rubs against the bone in the groove of the femur, causing friction— a bit of chafing that you can’t prevent with BodyGlide, unfortunately!
There doesn’t seem to be one generally accepted cause of runner’s knee. Some thoughts are biomechnical problems, weak quadriceps, or overtraining. A study recently published in the British Journal of Sports Medicine Online First took a closer look at some of the factors of a runner’s gait, including pronation, that are thought to contribute to patellofemoral pain.
At the beginning of the study, the researchers from Ghent University in Belgium measured the standing foot posture and running plantar pressure of novice recreational runners who were enrolled to begin a 10-week “start-to-run” program and who had no previous lower leg or knee injuries.
Of the 102 participants who then completed the training program designed to ready runners for a 5k, 17 (16 women and 1 man) developed patellofemoral pain. When the researchers looked at the plantar pressure measurements taken at the beginning of the study, they saw that the forces under the lateral heel during heel strike and the second and third metatarsals during the propulsion phase of running were significantly higher in the runners who developed patellofemoral pain than in those who did not.
Interestingly, they did not see an association between the static foot posture, nor the force distribution during foot roll-over, and development of patellofemoral pain. So, in this study anyway, pronation and supination didn’t have anything to do with it. Instead, study authors wonder whether the pain is caused by a higher impact shock overloading the knee joint. But, results from future studies are needed to know for sure. Until then, the jury’s out on the cause of runner’s knee.
- Recent Posts from This Author’s Blog