Lateral Perspective of the Infraspinatus Muscle

Description

Viewed laterally on an adult male skeleton, the scapula sits posterior to the rib cage and lateral to the thoracic vertebral column, with the scapular spine dividing the supraspinous and infraspinous fossae. The infraspinatus occupies the infraspinous fossa inferior to the scapular spine, its fibers converging laterally toward the greater tubercle of the proximal humerus, deep to the deltoid. Anteriorly, the clavicle spans to the acromion, framing the superior aspect of the glenohumeral region. Clear bony landmarks. Rotator cuff anatomy reads best from the lateral shoulder because you can track how the infraspinatus tendon passes posterior to the glenohumeral joint capsule and blends with it before inserting on the greater tubercle, a relationship that explains posterior shoulder pain patterns and weakness of external rotation. This is the muscle targeted during rotator cuff evaluation with resisted external rotation and during ultrasound or MRI assessment of tendinopathy and full thickness tears, which often coexist with posterosuperior labral pathology in overhead athletes. For surgeons, the view also aligns with posterior and posterolateral portals used in shoulder arthroscopy, where the infraspinatus lies deep to the deltoid split and must be respected to avoid iatrogenic injury. Use this asset in gross anatomy and kinesiology teaching to anchor scapular surface anatomy, rotator cuff function, and the relationship between the scapula, humerus, and deltoid covering. It also suits orthopedic and sports medicine chapters discussing rotator cuff tears, impingement patterns at the greater tuberosity, and physical exam maneuvers for external rotators. Anatomical accuracy verified by SciePro's Medical Advisory Board.