Patellar tendinitis

Not to be confused with Runner's knee which often affects runners; or Sinding-Larsen and Johansson syndrome and Osgood-Schlatter disease which primarily affect young athletes.

Patellar tendinitis (patellar tendinopathy, also known as jumper's knee), is a relatively common cause of pain in the inferior patellar region in athletes. It is common with frequent jumping and studies have shown it may be associated with stiff ankle movement and ankle sprains.