Patellar (knee) tendonitis is a sports injury that commonly affects elite athletes. Over time, repeated movements (such as jumping) gradually weaken the patellar tendon in the knee. This knee injury may cause minor to severe pain and discomfort. Left untreated, pain may worsen over time. Rest, rehab exercises and stretching may help your body heal.
The patellar tendon connects the bottom of the kneecap (patella) to the top of the shinbone (tibia). Despite its name, the patellar tendon is actually a ligament. Tendons connect a muscle to a bone. Ligaments connect two muscles.
The patellar tendon provides stability, holding bones together. It also works in tandem with the quadriceps (thigh) muscle and other connective tissues to help you move. You couldn’t straighten your knee or jump without it.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Patellar tendonitis happens when the patellar tendon tissue becomes inflamed (swollen) or irritated. Overuse usually causes this knee injury. It typically affects athletes at the height of their game.
Patellar tendonitis may cause minor to severe knee pain. Pain tends to worsen over time. Left untreated, pain and soreness may become debilitating. Patellar tendonitis pain may affect your athletic performance. In severe cases, it may stop you from participating in an activity altogether.
Jumper’s knee is another name for patellar tendonitis. This injury commonly affects professional basketball and volleyball athletes. Repeated jumping motions slowly strain the patellar tendon over time.
Patellar tendonitis happens when someone pushes knee tendon tissues too far, or too fast, over and over again. Repeated jumping and sprinting motions stress and strain the bands of patellar tendon tissues. Over time, lots of minor strains and tiny tears make the tendon tissues weak and sore.
This injury happens slowly over a long time. Medical experts still have unanswered questions about how or why patellar tendonitis occurs. Healthcare providers believe two main types of activities damage tendon tissues:
Yes. Patellar tendon tears (or ruptures) are acute injuries that happen suddenly. In some cases, repeated overuse over a long time can cause the patellar tendon tissue to abruptly tear.
Patellar tendon tears often happen when you land from a jump or suddenly change direction while running. A rip may go partway or all the way through tendon tissue.
Anyone can get tendonitis. Tendonitis can affect tendons in many areas of the body, such as the elbow, shoulder or hip.
Certain factors can affect your likelihood of developing patellar tendonitis:
Any activity that puts a lot of stress on your knee (such as from repeated jumping) could increase your risk of developing patellar tendonitis. These activities include:
Symptoms of patellar tendinitis include:
Patellar tendonitis symptoms usually get worse, slowly. At first, you may feel only minor knee pains. Discomfort may happen rarely, and only after physical activity. Over time, pain may get sharper and more severe. You may start to feel pain during physical activity.
If left untreated, patellar tendonitis can sometimes become debilitating. Symptoms may make routine tasks (such as climbing stairs or standing up) painful. Even sitting may cause discomfort.
To diagnose patellar tendonitis, your healthcare provider will first take a thorough medical history. That may include asking you about your activity level and symptoms. Be sure to tell your provider if your symptoms have changed over time.
Your provider will perform a physical exam to evaluate your symptoms. They may press all along your patellar tendon knee to gauge where it hurts. Gently moving your knee in different directions can help your provider evaluate your range of motion.
Imaging tests don’t always capture clear details of subtle overuse injuries to tendon tissues. However, your provider may order an X-ray to rule out other potential causes of your pain around your kneecap. In advanced or prolonged cases of patellar tendonitis, both ultrasound and MRI can observe structural damage to the patellar tendon.
Patellar tendonitis treatments mostly focus on managing your symptoms and strengthening the soft tissues in your knee. At first, your provider may ask you to try conservative therapies, such as rest. In minor cases, these measures may be enough to relieve your pain.
If the condition doesn’t go away, your provider may recommend you:
To reduce your risk of a sports injury, take these steps before you start any physical activity:
Healing takes time. The details of your recovery (such as what it looks like and how long it takes) will depend on many factors that are specific to you.
You may start feeling better after a few weeks of taking it easy. Yet someone with more severe patellar tendonitis may find it challenging to stay on top of chronic pain.
Try not to rush your body through recovery. Pushing your body before it’s fully healed can damage tendon tissues more, which may set your recovery back.
Reach out to your provider for an evaluation if you experience:
If you have patellar tendonitis, you may want to ask your provider:
A note from Cleveland Clinic
Recovering from a sports injury such as patellar tendonitis can be frustrating. You may feel tempted to cut your recovery short. But pushing your body too fast, too soon, has the potential to further damage already weakened tendon tissues. Instead, consider sitting down with a provider you trust to talk openly about your expectations. Work with your provider to develop a treatment and rehabilitation plan that fits your goals and prioritizes your long-term health.
Last reviewed by a Cleveland Clinic medical professional on 04/19/2021.
Learn more about our editorial process.