The shoulder anatomy is complex. There are three “joints” that make up the shoulder complex. The first is the main ball-and-socket joint (glenohumeral joint). The second joint is the junction of the outer end of the collar bone and the top of the shoulder blade (acromioclavicular joint). The third and final joint is the junction between the shoulder blade and the rib cage (scapulothoracic joint). The joint surfaces at the glenohumeral and acromioclavicular joints are covered with cartilage. The labrum is attached to the socket (glenoid) and helps with stability of the joint.
There are many muscles/tendons that help the joint move. The rotator cuff tendons (group of four muscles and tendons) help us reach away from our bodies, reach overhead, and behind our backs. The long head of the biceps also enters the shoulder joint and may play a role in joint positioning. Please click on the links below to navigate the area that interests you.