Runner's Knee

Runners are far more likely to suffer knee pain than cyclists. The most common long term injury in runners is a condition called runner�s knee in which the back of the knee cap rubs against the front bottom of the femur, the long bone of the upper leg. If it hurts to push the kneecap against the bone behind it, you have runner's knee.

The back of the kneecap is shaped like a triangle with the point fitting in a groove in the lower part of the bone behind it. During running, the knee cap is supposed to move up and down and not from side to side. When you run, you land on the outside bottom of your foot and roll inward toward the big toe side of your foot. This is called pronation. It forces your lower leg to twist inward while at the same time, three of the four quad muscles attached to the kneecap pull the kneecap outward, causing it to rub against the bone behind it.

The amount of inner twisting of the lower leg during running is related to how straight your knee is. Bending your knee decreases inner twisting and rubbing of the knee cap against the bone behind it. People with runner�s knee usually can pedal a bicycle with their seats set lower than normal to prevent their knees from straightening completely. Orthotics, custom- fitted inserts in the shoes that restrict pronation, may help. They can also use special exercises that strengthen the vastus medialis muscle above the kneecap that pulls the knee cap inward when they run or pedal.

Checked 6/29/09

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