The teres minor is a small, cylindrical muscle located in the shoulder region. It is part of the rotator cuff, a group of muscles and tendons that stabilize the shoulder joint. The teres minor originates from the lateral border of the scapula and inserts into the greater tubercle of the humerus. Its primary function is to assist in the external rotation of the arm. This muscle works in conjunction with other rotator cuff muscles, such as the infraspinatus and supraspinatus, to provide stability and mobility to the shoulder. Strengthening the teres minor can help prevent injuries and improve overall shoulder function, making it important for athletes and active individuals.