Information About Tendinitis (Tendonitis)

Tendinitis is inflammation or irritation of a tendon — the thick fibrous cords that attach muscles to bone. This causes pain and tenderness just outside a joint. Tendinitis is most common in shoulders, elbows and knees but can also occur hips, heels and wrists.

Tendons are usually surrounded by a sheath of tissue similar to the lining of the joints (synovium). They're subject to the wear and tear of aging, direct injury and inflammatory diseases.

Common names for tendinitis include tennis elbow, golfer's elbow, pitcher's shoulder, swimmer's shoulder and jumper's knee.

You have a greater risk of developing tendinitis if you perform excessive repetitive motions of your arms or legs. For instance, professional baseball players, swimmers, tennis players and golfers are susceptible to tendinitis in their shoulders, arms and elbows. Soccer and basketball players, runners and dancers are more prone to tendon inflammation in their legs and feet. But you don't have to be a professional athlete to develop this condition. The incidence of tendinitis increases with age as muscles and tendons lose some of their elasticity. Improper technique in any sport is one of the primary causes of overload on tissues, including tendons, which can contribute to tendinitis.

Injury or overuse during work or play is the most common cause of tendinitis. The pain is usually the result of a small tear in or inflammation of the tendon that links your muscles to your bone. Tendinitis can also be caused by inflammatory diseases that occur in your body, such as rheumatoid arthritis.