Rotator cuff tendon at the entrance of the bicipital groove. The supraspinatus is most commonly involved in a rotator cuff tear. The rotator cuff muscles are important in shoulder movements and in maintaining glenohumeral joint (shoulder joint) stability. These muscles arise from the scapula and connect to the head of the humerus, forming a cuff at the shoulder joint. They hold the head of the humerus in the small and shallow glenoid fossa of the scapula. The glenohumeral joint has been analogously described as a golf ball (head of the humerus) sitting on a golf tee (glenoid fossa). During abduction of the
Posterior compartment of the forearm De Quervain's syndrome is a medical condition when the synovial sheath surrounding tendons in the first extensor tendon compartment becomes inflamed, so called tenosynovitis. The tendons of the abductor pollicis longus and the extensor pollicis brevis run narrower due to the thickening of the synovial sheath, which causes pain when extending and moving the thumb outward. Carpal tunnel syndrome is a condition when the median nerve is compressed as it passes through the carpal tunnel, which causes pain, numbness and tingling. The presence of an additional tendon may result in a condition called fourth compartment syndrome. Supernumerary tendons are common