This condition is an inflammation of the tendon that connects the patella (the kneecap) to the tibia in the knee joint. This tendon is part of the structure of muscles and tendons in the knee that allows the knee to straighten from being bent.

Patellar tendonitis occurs when the patellar tendon becomes irritated and inflamed, most commonly from overuse from strenuous physical activity. Athletes who participate in jumping sports such as basketball or volleyball are particularly susceptible. In some rare cases, patellar tendonitis can be caused by an injury or trauma to the knee.

The most common symptom of patellar tendonitis is pain, directly over the patellar tendon, just below the kneecap. This pain often increases during physical activity. Other symptoms can include swelling and loss of mobility in the knee joint.

Treatment options include rest, cold compress, anti-inflammatory medications, stretching exercises, physical therapy, or use of a brace or support. Severe cases may require surgery.