The muscles of the shoulder either connect the scapula and clavicle to the trunk, or connect the clavicle, scapula and body wall to the proximal (top) end of the humerus. The trapezius, levator scapulae, and rhomboids originate from the base of the skull and/or spine and connect the scapula and clavicle to the trunk of the body. The pectoralis major, pectoralis minor, latissimus dorsi, teres major and deltoid connect to the proximal end of the humerus and anchor it to the body.These shoulder muscles can be separated into three important groups:
1. Superficial muscles (Extrinsic)
3. Muscles of the shoulder & arm