Upper Back Muscles Beneath the Skin, Posterior View

Description

Posteriorly, the upper dorsum is dominated by the trapezius spanning from the external occipital protuberance and nuchal ligament inferiorly to the thoracic spinous processes, then laterally to the acromion and spine of the scapula. Inferior and lateral to its caudal fibers, the latissimus dorsi broadens over the lower thoracic region and approaches the posterior axillary fold, while the medial border of the scapula is framed by the rhomboid major and minor deep to trapezius. Along the posterior shoulder, the infraspinatus occupies the infraspinous fossa and runs laterally to the greater tubercle, with teres minor just inferior to it and the posterior deltoid forming the rounded lateral contour of the shoulder. Fiber direction cues help orient function. Fast. Scapulothoracic mechanics live in this anatomy, and this posterior view makes scapular positioning errors easy to teach: rhomboid weakness or trapezius imbalance shifts the medial border and inferior angle, producing scapular dyskinesis during overhead motion. Injury to the spinal accessory nerve (CN XI) after cervical lymph node biopsy or neck dissection can denervate trapezius, leading to shoulder droop and impaired upward rotation that clinicians often correlate with lateral scapular winging. At the glenohumeral level, the infraspinatus and teres minor form the posterior rotator cuff, a common site of tendinopathy in throwers and a key landmark during posterior shoulder approaches and arthroscopic portal planning. Use this asset for gross anatomy labs covering the superficial and intermediate back, for kinesiology modules on scapular upward rotation and posterior cuff function, or as a clean figure in sports medicine and orthopaedic texts discussing rotator cuff tears, scapular winging, and upper back strain patterns. It also fits patient education on postural retraining and periscapular strengthening after shoulder injury. Anatomical accuracy verified by SciePro's Medical Advisory Board.