Infraspinatus Under the Skin

Description

Seen from a posterior, subcutaneous perspective of the male upper back, the scapular spine divides supraspinous and infraspinous fossae while the infraspinatus occupies the infraspinous fossa and sweeps laterally toward the humeral head. Oblique muscle fibers converge into a thick tendon that passes deep to the posterior deltoid and inserts on the middle facet of the greater tubercle of the humerus, adjacent to the posterior glenohumeral capsule. Bony landmarks remain prominent under the skin, including the vertebral column, posterior ribs, acromion, medial border and inferior angle of the scapula, and the proximal humerus. Orientation is clear. For rotator cuff teaching, this posterior view clarifies why isolated infraspinatus weakness presents as loss of resisted external rotation with the arm at the side, and why posterior shoulder pain often localizes around the scapular spine and lateral border. The relationship of the infraspinatus tendon to the greater tubercle matters during arthroscopic cuff repair, where the posterior portal trajectory and anchor placement must respect the footprint and avoid overtensioning that limits postoperative external rotation. It also helps when explaining suprascapular nerve entrapment at the spinoglenoid notch, a lesion that preferentially denervates infraspinatus and produces selective atrophy in the infraspinous fossa. Use this plate in gross anatomy lab guides, sports medicine and orthopaedics lectures on rotator cuff anatomy, and surgical atlases describing posterior shoulder approaches and arthroscopic orientation. It also suits patient education materials on rotator cuff tears and rehabilitation focused on external rotator strengthening in men. Anatomical accuracy verified by SciePro's Medical Advisory Board.