Tendons are tissues that connect muscles to bone. 
The tendons in your knees are subject to injuries, including tendinitis&mdash;when they become swollen and painful&mdash;and tearing, also called rupture. 
Causes 
Tendinitis can occur after overuse. Doing a lot of dancing, bicycling or running can stretch out tendons and leave them sore, says the <a href="[BASEDOMAIN]/healthinfo/bouncelink.aspx?shortcut=niams" target="_blank">National Institute of Arthritis and Musculoskeletal and Skin Diseases</a> (NIAMS). 
A type of tendinitis called jumper's knee can affect people who play basketball and other sports that require a lot of jumping. The tendon can hurt and swell and may even tear after repeated stress. 

A tendon may rupture when a person tries to break a fall. This is especially common in older people, whose tendons tend to be weaker, the NIAMS says. 
Signs and symptoms 
Tendinitis can make the knee joint feel tender around the kneecap. There is sometimes pain when running, walking quickly or jumping. 
A ruptured tendon is painful and makes it difficult to lift or bend the knee. 
A doctor may use magnetic resonance imaging (MRI) or an x-ray to check for a tear. 
Treatment 
The typical treatment for tendinitis is to rest the knee, keep it elevated and apply ice. Pain relievers, such as aspirin or ibuprofen, can reduce pain and swelling. If it doesn't improve, your doctor may want to try corticosteroid injections.
Surgery is sometimes needed to reattach tendons that have completely torn, the NIAMS says.&nbsp;&nbsp;
A doctor will likely prescribe exercise as part of rehabilitation for a partially or completely torn tendon. Rehabilitation can take up to six months. 
Reviewed 11/29/2023

Knees: Tendon injuries

Wear and tear on the knees can result in tendinitis or a ruptured tendon. Recognizing the symptoms can help you avoid further injury.