The most common cause of knee pain is runner’s knee, known medically as chondromalacia patella. This is due to misalignment of the kneecap in its groove. The kneecap normally goes up or down in the groove as the knee flexes or straightens out. If the kneecap is misaligned, the kneecap pulls off to one side and rubs on the side of the groove. This causes both the cartilage on the side of the groove and the cartilage on the back of the kneecap to wear out. On occasion, fluid will build up and cause swelling in the knee.

Runners are not the only ones who develop runner’s knee. Pain can develop around the back of the kneecap or in the back of the knee after participating in any running sport.

The best treatment for these injuries is to strengthen quadriceps muscles. It is also recommended that stretching exercise is done to help movement.