Teres minor is one of the rotator cuff muscles around the glenohumeral joint. It acts to stabilise the shoulder joint and laterally rotate the arm. Functionally, it acts as an extension of infraspinatus which lies superiorly.
It arises from the superior and middle parts of the lateral border of the scapula and a small area of the adjacent dorsal surface of the bone. Its main insertion is into the inferior facet of the greater tuberosity of the humerus. Also, it supplies some fibres to the joint capsule.
Teres minor is innervated by the axillary nerve (C5, C6) which arises from the posterior cord of the brachial plexus.