Patellofemoral pain syndrome is pain in the front of the knee. It is caused by overuse, weak thigh muscles (quadriceps), or a problem with the way the kneecap moves. Extra weight may also cause this syndrome.
The patella is the kneecap, and the femur is the thighbone.
Some people may have pain in the front of the knee from a condition called chondromalacia. In this problem, the underside of the knee cartilage wears down and frays. Cartilage is a rubbery tissue that cushions joints.
In some cases, the kneecap does not move, or track, in a normal way. You may have knee pain when you run, walk down hills or steps, or do another activity. Sitting for a long time also can cause knee pain.
Your knee pain may get better with medicines for pain and swelling and exercises to make your quadriceps stronger. Losing weight, if you need to, may also help with pain.