Teres minor

The teres minor (Latin: musculus teres minor) is a narrow muscle of the upper limb located in the shoulder region. It stretches between the scapula and the head of the humerus. The teres minor muscle is one of the muscles of the shoulder girdle, and it participates in the stabilization of the shoulder joint. Together with the supraspinatus, infraspinatus and subscapularis, it belongs to the rotator cuff muscles.

Origin

The teres minor muscle arises from the lateral border of the scapula.

Insertion

The fibers of the teres minor pass laterally to the humerus and insert on the greater tubercle of the humerus.

Action

The teres minor muscle stabilizes the glenohumeral (shoulder) joint and provides external (lateral) rotation of the arm at the shoulder joint.

Innervation

The teres minor is innervated by the axillary nerve that arises from the fifth and sixth cervical (C5, C6) nerve roots of the brachial plexus.

Blood supply

The arterial blood to the teres minor muscle is supplied mainly by the circumflex scapular and posterior circumflex humeral arteries. The first artery is a branch of the subscapular artery, while the latter is from the axillary artery.