Jumping sports (such as basketball and volleyball) put a huge load on the kneecap and attached tendons. Signs and symptoms of patellar tendonitis include pain to touch directly on the patellar tendon and occasionally, swelling. Treatment includes activity modification, and physical therapy.

Sinding-Larsen-Johansson is a specific disorder of the patellar tendon where it attaches to the base of the kneecap. In contrast, Osgood-Schlatter disease is a disorder of the tendon where it attaches at the tibial tuberosity of the leg. Both are common disorders in maturing teens. Treatment includes activity modification, physical therapy, and rarely surgical excision of the associated necrotic debris.