Muscles of the Shoulder

The deltoid is undivided; it arises from the aponeurosis covering the infraspinatus, and it ends largely on the deltoid ridge, but partly on the fascia of the arm.

The supraspinatus is large; it ends chiefly on the external tuberosity of the humerus.

The infraspinatus is inserted into a depression below the posterior division of the external tuberosity.

The teres minor is well developed; it ends on a tubercle between the external and deltoid tuberosities of the humerus.

The subscapularis and teres major have no remarkable features.

The coraco-brachialis is short and undivided.

The capsularis is very small and frequently absent.