Shoulder Muscles Under the Skin

Description

Posterior shoulder musculature is rendered beneath a semi-translucent skin layer, with the deltoid draping laterally from the acromion and scapular spine onto the proximal humerus. Superiorly, the trapezius spans from the cervical region to the scapular spine, framing the scapula medially, while the infraspinatus occupies the infraspinous fossa inferior to the spine of the scapula. Along the lateral border of the scapula, teres minor sits superior to teres major, and the latissimus dorsi sweeps inferolaterally toward the humerus to form the posterior axillary fold. Fiber direction is clear. Emphasis on these posterior compartments helps when teaching scapulohumeral rhythm and the mechanics of external rotation, where infraspinatus and teres minor act across the glenohumeral joint beneath the posterior deltoid. This angle also aligns with common clinical patterns: posterior shoulder pain from rotator cuff tendinopathy, infraspinatus atrophy with suprascapular nerve entrapment at the spinoglenoid notch, and the typical location of posterior deltoid splitting approaches used to access the cuff while respecting the course of the axillary nerve deep to the deltoid. Surface contour matters in exam and injection planning. Palpable landmarks such as the scapular spine and acromion guide safe positioning when targeting the subacromial space or glenohumeral joint. Use this artwork for gross anatomy and kinesiology courses covering the shoulder girdle, as well as orthopaedic, sports medicine, and physical therapy teaching on rotator cuff function and scapular stabilizers. It also fits surgical atlases, clinical slide decks on shoulder impingement and cuff tears, and patient-facing education where a realistic male posterior shoulder surface helps connect symptoms to underlying muscles. Anatomical accuracy verified by SciePro's Medical Advisory Board.