The muscle is inserted by a flattened, bilaminar tendon, chiefly into the lateral lip of the bicipital groove of the humerus.
The pectoralis major is supported by the lateral and medial pectoral nerves. As a whole it is an adductor and medial rotator of the upper limb; and, when the limb is thrust forward or backward by movements of the scapula, the pectoralis major assists in pulling it back again to the vertical position. The clavicular head, acting with the anterior fibers of the deltoid muscle, is an active agent in flexion of the arm at the shoulder joint, a movement which can be reversed by the sternocostal head.
Related category ANATOMY AND PHYSIOLOGY
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