Updated: Dec 21, 2019
  • Author: Mark Steele, MD; Chief Editor: Herbert S Diamond, MD  more...
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Practice Essentials

Tendonitis is an inflammatory condition characterized by pain at tendinous insertions into bone. The term tendinosis refers to the histopathologic finding of tendon degeneration. The term tendinopathy is a generic term used to describe a common clinical condition affecting the tendons, which causes pain, swelling, or impaired performance. Because of the fact that most pain from tendon conditions is not actually inflammatory in nature, tendinopathy may be a better term than tendonitis.

Common sites of tendinopathy include the following:

  • Rotator cuff of the shoulder (ie, supraspinatus) and bicipital tendons
  • Insertion of the wrist extensors (ie, lateral epicondylitis, tennis elbow) and flexors (ie, medial epicondylitis) at the elbow
  • Patellar and popliteal tendons and iliotibial band at the knee
  • Insertion of the posterior tibial tendon in the leg (ie, shin splints)
  • Achilles tendon at the heel


Tendons transmit the forces of muscle to the skeleton. As such, they are subjected to repeated mechanical loads, which are felt to be a major causative factor in the development of tendinopathy. Pathologic findings include tendon inflammation, mucoid degeneration, and fibrinoid necrosis in tendons. Microtearing and proliferation of fibroblasts have also been reported. However, the exact pathogenesis of tendinopathy is unclear.



Middle-aged adults are most susceptible to the development of tendinopathy.



In general, the prognosis is very good with rest and conservative therapy. Chronic tendinopathy can lead to weakening of the tendon and subsequent rupture. Complications of tendonitis may include chronic disability, tendon rupture, and adhesive capsulitis (ie, frozen shoulder).


Patient Education

Quadriceps strengthening exercises is helpful for patellar tendinopathy and change in training routine and/or equipment, if indicated. Runners with Achilles tendinopathy should wear proper footwear, run on softer surfaces, and avoid hills. Patients with tennis elbow should maintain proper backhand technique, use a less tightly strung racket, and play on slower surfaces. Range-of-motion exercises are recommended for patients with rotator cuff tendinopathy to avoid complication of adhesive capsulitis.

For patient education information, see Tendinitis and Tennis Elbow.