What is shoulder tendonitis?
The most common form of tendonitis in the shoulder is rotator cuff tendonitis. It involves the tendon of the supraspinatus muscle, which attaches to the upper portion of the upper arm bone (humerus) at the shoulder joint. Less commonly, the tendon of the infraspinatus muscle is affected. In most cases, the supraspinatus tendon is injured by overuse, typically in an occupation or sport that requires the arm to be elevated repeatedly. People at risk include carpenters, painters, welders, swimmers, tennis players and baseball players. The average patient is a male laborer older than 40, and the shoulder pain is on the same side as his dominant hand (for example, right shoulder pain in a right-handed person).
