The clavicle and scapula form the shoulder girdle. This acts as the bony framework by which the muscles of the chest, upper back and shoulder connect the upper limb to the trunk of the body and control it’s movements.The clavicle connects to the sternum via the sternoclavicular joint and to the scapula by the acromioclavicular joint. A fractured clavicle is the most frequently broken bone in the body. Attaching to the clavicle are the pectoralis major, sternocleidomastoid, deltoid and trapezius muscles.
The serratus anterior arises from the ribs and inserts on the medial (vertebral) border of the scapula. The serratus anterior pulls the medial edge of the scapula in towards the body wall, preventing it from protruding outwards as a “winged scapula”.
The upper arm contains four muscles: the coracobrachialis (not shown), biceps brachii, brachialis, and triceps brachii.