Patellar Tendinitis (Jumper's Knee)

What patellar tendinitis is

The patellar tendon transfers the force of the quadriceps muscle to the shin, letting you straighten the knee and absorb landing forces. When jumping, the tendon can carry several times your body weight. If that load repeatedly exceeds what the tendon can adapt to, its collagen fibers become disorganized and painful.

Despite the name, the tendon is usually not truly inflamed. That is why experts now prefer patellar tendinopathy, which describes a degenerative, poorly healing tendon. The patellar tendinopathy page covers the tendon changes and imaging in more detail; this page focuses on symptoms, self-management and rehabilitation.

Symptoms

• pain and tenderness at the lower tip of the kneecap, very localized
• pain that starts with activity, may ease once warmed up, then returns afterward
• pain going up or down stairs, squatting, kneeling or after sitting for long periods
• stiffness in the morning or after rest
• in advanced cases, pain with daily activities and at rest

Stages of jumper's knee

Causes and risk factors

• Training load: a sudden increase in jumping, running, plyometrics or games, especially in-season or after time off.
• Sports: basketball, volleyball, high and long jump, soccer, tennis, running on hard surfaces.
• Muscle factors: tight quadriceps and hamstrings, weak hip and thigh muscles, stiff ankles that shift more landing load to the knee.
• Landing technique: stiff-legged or knee-dominant landings.
• Body weight and age: more common in heavier athletes and those in their late teens to 30s.

Patellar tendinitis vs other front-of-knee pain

Diagnosis

A clinician presses on the lower tip of the kneecap, checks pain during a single-leg squat or decline squat, and tests strength and flexibility. Ultrasound may show a thickened tendon with abnormal blood vessels; MRI is used when the diagnosis is unclear or before surgery. X-rays are usually not needed but can rule out bone problems in children.

Treatment

Manage the load, do not stop completely

Reduce or pause the activities that provoke pain, such as jumping and deep squatting, but stay active. A useful rule: pain up to about 3 out of 10 during exercise is acceptable, as long as it settles by the next morning.

Rehabilitation exercises

Progressive loading is the treatment with the strongest evidence. A typical program, guided by a physical therapist, has four stages:

1. Isometric holds: wall sits or holding a leg extension at about 60 degrees bend, 5 holds of 30 to 45 seconds, several times a day. They often reduce pain right away.
2. Isotonic strengthening: slow, heavy leg presses, squats and leg extensions, about 3 to 4 sets, 3 times a week, increasing weight over weeks. Decline squats on a slanted board load the tendon specifically.
3. Energy storage: reintroduce jumping, skipping and hopping once strength is good, starting with low volumes.
4. Return to sport: sport-specific drills, then full training and competition.

Also work on hip and calf strength, flexibility of the quadriceps and hamstrings, and softer landing technique.

Other measures

• Ice for 15 minutes after activity can ease pain.
• Pain relievers: acetaminophen (paracetamol) or NSAIDs such as ibuprofen for short-term relief, following the label dose. NSAIDs do not heal the tendon.
• Patellar tendon strap: a band below the kneecap helps some people during sport.
• Shock wave therapy (ESWT): may help persistent cases alongside exercise.
• Injections: platelet-rich plasma is sometimes used for stubborn cases, with mixed evidence. Steroid injections are generally avoided because they can weaken the tendon and raise the risk of rupture.
• Surgery: removal of damaged tendon tissue, by open or arthroscopic surgery, for the small number not improving after 6 to 12 months of good rehab.

Recovery time

Mild, early tendinitis may settle in 6 to 8 weeks. Most cases need 3 to 6 months of consistent loading exercises. Long-standing jumper's knee can take longer and may flare when training increases. Ignoring the pain and continuing full training raises the risk of chronic problems and, rarely, a patellar tendon rupture.

Prevention

• Increase training volume gradually, about 10% a week or less.
• Include strength work for the quadriceps, hips and calves year-round.
• Practice soft, bent-knee landings.
• Build recovery days into heavy jumping schedules.

Frequently asked questions

How do I know if I have patellar tendinitis?

The key sign is pain at the bottom tip of the kneecap, sharply localized, that comes on with jumping, running, squatting or stairs. It may ease once you warm up and return afterward. Tenderness when pressing just below the kneecap supports the diagnosis.

How long does patellar tendinitis take to heal?

Early, mild cases may settle in 6 to 8 weeks. Most people need 3 to 6 months of progressive strengthening to return fully to jumping sports. Cases that have been present for a year or more can take longer, and flare-ups are common if training increases too fast.

What exercises help jumper's knee?

Start with isometric holds, such as wall sits or a static leg extension, for pain relief. Then progress to slow, heavy squats, leg presses and decline squats. Finally add hopping and jumping drills before returning to sport. A physical therapist can tailor the program.

Should I stop running with patellar tendinitis?

Not necessarily. You can often continue running or sport at a reduced level if pain stays mild (about 3 out of 10 or less) and settles by the next morning. Reduce jumping and hills first. Complete rest weakens the tendon and slows recovery.

Does a knee strap help patellar tendinitis?

A patellar tendon strap worn just below the kneecap reduces pain during activity for some people by changing how force passes through the tendon. It is a helpful add-on but does not heal the tendon, so it should be combined with a strengthening program.