Also known as jumper's knee, this is inflammation of the tendon of the extensor muscle of the thigh, to which the PATELLA or knee-cap is secured. Usually the result of injury or excessive use or stress – for example, in athletic training – symptoms may include pain, tenderness, and restricted movement of the parent muscle. Treatment may include NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), ULTRASOUND treatment and PHYSIOTHERAPY, and, if persistent, injection of a corticosteroid drug (see CORTICOSTEROIDS) around the tendon.