Jumper’s Knee

There is a symptom that identifies this condition more reliably than almost any test. Sitting with your knee bent for a long period hurts. A long car journey. A flight. A cinema. You get out stiff and sore at the front of the knee, and you find yourself straightening the leg out or shifting position to relieve it.
Combine that with pain just below the kneecap that warms up during activity and is worse the next morning, and you have the characteristic picture of patellar tendinopathy.