Infrapatellar Tendinitis

(Jumper’s Knee; Sinding-Larsen-Johansson Syndrome)

ByEsra Meidan, MD, Boston Children's Hospital
Reviewed/Revised Modified Oct 2025
v37718087
VIEW PROFESSIONAL VERSION

Infrapatellar tendinitis is inflammation of the tendon under the kneecap (patella) caused by overuse of the knees due to running or jumping.

Tendons are tough bands of connective tissue that attach each end of a muscle to a bone. Tendinitis is inflammation of a tendon.

Infrapatellar tendinitis typically affects children aged 10 to 13 years. It usually occurs in figure skaters and basketball or volleyball players. The overuse of the knees causes very small tears and inflammation to occur in the tendon under the kneecap (patella).

This disorder causes knee pain and tenderness. The pain is worst when straightening the knee while climbing stairs, jumping, or doing knee bends.

A doctor bases the diagnosis of infrapatellar tendinitis on the child's history and physical examination but may do magnetic resonance imaging (MRI) or an ultrasound to evaluate the extent of the injury.

Treatment of Infrapatellar Tendinitis

  • Measures to relieve pain and rest the knee

To relieve the pain, children are told to rest and modify their athletic activities, take nonsteroidal anti-inflammatory drugs (NSAIDs), and do physical therapy. Taping the knee in specific patterns may also help relieve pressure on the patellar tendon.

Persistent pain may be treated surgically, but this is usually not necessary.

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