Teres Minor Muscle

Description

Positioned along the posterolateral scapula, the teres minor muscle is shown arising from the upper two thirds of the lateral border of the scapula and coursing laterally to its insertion on the inferior facet of the greater tubercle of the humerus. Superiorly it lies just inferior to the infraspinatus, while inferiorly it is separated from teres major by the long head of the triceps brachii as that tendon descends from the infraglenoid tubercle. A posterior view also brings the scapular spine, acromion, and posterior thoracic wall into clear relationship with the rotator cuff. This anatomy is tight. As the posterior component of the rotator cuff, teres minor contributes to glenohumeral external rotation and, with infraspinatus, compresses the humeral head into the glenoid during overhead motion. Distinguishing teres minor from teres major matters in surgical planning and reporting, since the long head of triceps defines the interval used to orient the quadrangular space (axillary nerve and posterior circumflex humeral artery) versus the triangular space and triangular interval. Fatty infiltration or denervation atrophy of teres minor, classically from quadrilateral space syndrome, is a specific pitfall on shoulder MRI and correlates with posterior shoulder pain in throwing athletes. Educators can drop this plate into gross anatomy labs, upper limb courses, and musculoskeletal modules when teaching scapulohumeral rhythm, rotator cuff function, and posterior shoulder spaces. It also suits orthopedic and sports medicine publications discussing posterior shoulder approaches, axillary nerve risk, or cuff tear patterns involving the infraspinatus and teres minor footprint on the greater tubercle. Anatomical accuracy verified by SciePro's Medical Advisory Board.