Patellar Tendinitis

Overview

Patellar tendinitis is an overuse injury of the patellar tendon, the strong band that connects the kneecap (patella) to the shinbone (tibia). This tendon works with the thigh muscles to straighten the knee, which is essential for jumping, running, and kicking. Repeated stress can cause small injuries and irritation in the tendon, leading to pain at the front of the knee just below the kneecap.

The condition is often called jumper's knee because it is common in athletes who jump frequently, such as basketball and volleyball players. Although it usually develops gradually, it can become persistent if not managed. Most cases improve with rest, targeted exercises, and a careful return to activity. The term tendinopathy is sometimes used because the problem often involves wear and tear rather than only inflammation.

Symptoms

The main symptom is pain in the front of the knee. Typical features include:

• Pain and tenderness just below the kneecap
• Discomfort that starts during or after activity, especially jumping, running, or squatting
• Stiffness in the knee, particularly in the morning or after sitting
• Pain when going up or down stairs or rising from a chair
• Worsening pain with continued activity if not addressed

Early on, the pain may appear only after exercise. As it progresses, it can occur during activity and even at rest. Persistent or severe knee pain should be evaluated.

Causes

Patellar tendinitis is caused by repeated stress on the patellar tendon, which leads to tiny injuries faster than the body can repair them. Contributing factors include:

• Frequent jumping and landing: Sports like basketball and volleyball place heavy load on the tendon.
• Sudden increases in training: Ramping up intensity, frequency, or duration too quickly.
• Hard playing surfaces: Which increase impact.
• Tight or weak thigh and leg muscles: Which place extra strain on the tendon.

Over time these stresses cause the tendon to weaken and become painful.

Risk Factors

• Participation in jumping sports such as basketball, volleyball, and high jump
• Rapidly increasing training load
• Tight quadriceps or hamstring muscles
• Muscle imbalances or weakness in the legs
• Being overweight, which adds load to the tendon
• Frequent training on hard surfaces

Diagnosis

A doctor or physical therapist can usually diagnose patellar tendinitis from the history and an examination:

• Physical exam: Pressing on the tendon below the kneecap reproduces the pain, and the knee is checked for strength and movement.
• Activity history: Noting jumping sports and recent changes in training.
• Imaging: Ultrasound or MRI may be used in unclear or persistent cases to look at the tendon and rule out other problems.

Treatment

Most people improve with conservative care focused on calming the pain and gradually strengthening the tendon:

• Relative rest: Reducing jumping and high-impact activity while keeping the knee moving.
• Ice and pain relief: Cold packs and, if appropriate, over-the-counter pain relievers for short-term comfort.
• Strengthening exercises: Gradual, guided exercises, especially eccentric quadriceps work, which are a cornerstone of recovery.
• Stretching: Of the thigh and calf muscles to reduce strain on the tendon.
• Gradual return to sport: Slowly increasing load as pain settles.

Recovery can take weeks to months. Persistent cases may need physical therapy or, rarely, other procedures. A slow, steady return helps prevent the problem from coming back.

Prevention

Patellar tendinitis can often be prevented or kept from returning with sensible training habits:

• Increasing training intensity and volume gradually
• Warming up properly and stretching the legs
• Strengthening the thigh, hip, and calf muscles
• Using good jumping and landing technique
• Allowing adequate rest and recovery between hard sessions
• Addressing early knee pain before it worsens

When to See a Doctor

See a doctor or physical therapist if knee pain below the kneecap persists despite rest, limits your activity, or keeps returning. Seek prompt evaluation if you have:

• Pain that occurs at rest or worsens over time
• Significant swelling, redness, or warmth in the knee
• An inability to straighten the knee or bear weight
• A sudden popping sensation with severe pain, which could indicate a tendon tear

Related Topics

Frequently Asked Questions

References

1. American Academy of Orthopaedic Surgeons (AAOS). Patellar Tendon Tear.
2. Mayo Clinic. Patellar tendinitis.
3. MedlinePlus, U.S. National Library of Medicine.
4. American Academy of Family Physicians (AAFP).