Shoulder joint Shoulder joint The shoulder joint (or glenohumeral joint from Greek "glene", eyeball, + -"oid", 'form of', + Latin "humerus", shoulder) is structurally classified as a synovial ball and socket joint and functionally as a diarthrosis and multiaxial joint. It involves articulation between the glenoid cavity of the scapula (shoulder blade) and the head of the humerus (upper arm bone). Due to the very loose joint capsule that gives a limited interface of the humerus and scapula, it is the most mobile joint of the human body. The shoulder joint is a ball and socket joint between the scapula and the
Upper extremity of humerus is an indentation distal to the head of the humerus on which the articular capsule attaches. The greater tubercle ("tuberculum majus"; greater tuberosity) is situated lateral to the head and lesser tubercle, and just lateral to the anatomical neck. Its upper surface is rounded and marked by three flat impressions: the highest of these gives insertion to the supraspinatus muscle; the middle to the infraspinatus muscle; the lowest one, and the body of the bone for about 2.5 cm. below it, to the teres minor muscle. The lateral surface of the greater tubercle is convex, rough, and continuous with the