Teres Minor Muscle Under the Skin, Posterior View

Description

Posterior integument has been conceptually removed to reveal the superficial contouring of the shoulder girdle, with the deltoid capping the glenohumeral joint and the teres minor highlighted along the lateral border of the scapula. Running obliquely from the dorsal surface of the scapula to the greater tubercle of the humerus, teres minor lies inferior to infraspinatus and superior to teres major, forming the superior margin of the quadrangular space. Lateral to the scapular spine, its tendon tracks deep to the posterior deltoid toward the posterior aspect of the humeral head. Clear landmarks. Trapezius, latissimus dorsi, erector spinae, and the posterior arm musculature provide regional context in the upper back and arm. This posterior perspective matters when you need to teach or plan around the rotator cuff’s posterior component and its relationship to neurovascular structures that traverse the quadrangular space, namely the axillary nerve and posterior circumflex humeral artery. Isolated teres minor atrophy can follow quadrilateral space syndrome or axillary nerve injury, and it changes the physical exam and MRI pattern in patients with posterolateral shoulder pain and weakness of external rotation. For surgeons, the spatial relationship between teres minor, infraspinatus, and the posterior deltoid mirrors the anatomy encountered with posterior shoulder arthroscopy portals and during posterior approaches to the proximal humerus. Use this illustration in gross anatomy labs when introducing scapulohumeral muscles, in orthopedic and sports medicine teaching on rotator cuff tear patterns, and in rehabilitation materials that differentiate teres minor function from infraspinatus during external rotation strengthening. It also supports surface anatomy and injection safety discussions by orienting learners to the posterior deltoid overlay and the deeper course of the axillary nerve. Anatomical accuracy verified by SciePro's Medical Advisory Board.