what causes knee pain that is not resulting from injury
Anterior knee pain. Knee pain felt at the front of the knee, around the kneecap, is called anterior knee pain or patellofemoral pain syndrome. It's not always obvious why this pain develops, but it's been linked to previous injuries, overuse of your knees, muscle weakness and your kneecap being slightly out of place.
A knee infection can be caused by a number of things including septic arthritis and a build-up of bacteria in the bursae. These infections can cause the knee to swell and feel warm. Intense pain and a fever may also accompany the infection.