There are three bones that make up the shoulder girdle; these include the scapula, the humerus and the clavicle. The shoulder girdle anatomy consists of various articulations that connect the arm to the skeleton and provide movement.
The scapula is the site of attachment for various muscles that support stabilization and movement of the actual shoulder. This bone has a socket that is shallow on the lateral side, where the humerus fits, and forms what is known as the glenohumeral joint.
The clavicle bone is S-shaped and is a major connection between the axial skeleton and the upper arm. This bone is the area for a number of muscle attachments which include the subclavius, sternohyoid, sternoclaedomastoid, trapezius and pectoralis major.
The humerus bone consists of a head, neck, shaft, and lesser and greater tubercles. The head part of the humerus has a half-spherical shape, and the head projects into what is known as the glenoid cavity. The neck part of the humerus bone is situated between the tubercles and the head. The tubercles that consist of lesser and greater components serve as the site of attachment for rotator cuff muscles.
The four joints that make up the shoulder joint are the glenohumeral joint, acromioclavicular joint, sternoclavicular joint and the scapulothoracic joint.