Knee injuries.

Patellofemoral pain syndrome (PFPS) is a frequently encountered overuse disorder that involves the patellofemoral region and often presents as anterior knee pain. PFPS is the most common cause of knee pain seen by primary care physicians, orthopedic surgeons, and sports medicine specialists. The terms runner’s knee, patellofemoral joint syndrome and chondromalacia patellae are also used to describe this condition. The pain comes from the joint under the kneecap ("patella") where it slides up and down over the thigh bone ("femur"). It causes an aching pain and often a rubbing sound in the front of the knee, usually worse after squatting and going up and down hills (steps). We do know some factors that contribute to it; for instance, the anatomy of your legs and kneecaps and whether you have fallen or banged your knees in the past. Some factors can be controlled: mainly the strength and flexibility of your muscles, amount of overuse, improper exercise techniques, and your weight.