Infraspinatus, Posterior View

Description

Occupying the infraspinous fossa on the posterior scapula, the infraspinatus spreads broadly from the scapular spine inferiorly toward the greater tubercle of the humerus, with its tendon passing deep to the posterior deltoid before blending into the rotator cuff. Along its inferior border, the muscle lies adjacent to teres minor laterally and teres major more inferiorly, while the medial edge approaches the scapular medial border near the attachments of rhomboid major and minor. Superior to the infraspinatus, the scapular spine separates it from supraspinatus in the supraspinous fossa. Clean landmarks. External rotation strength and posterior shoulder stability live or die here, so a posterior view centered on infraspinatus helps you teach how cuff tendons coapt the humeral head against the glenoid during abduction and overhead work. Clinically, fatty atrophy of infraspinatus with preserved supraspinatus can point toward suprascapular nerve compression at the spinoglenoid notch, a pattern often discussed in overhead athletes and in paralabral cysts. Rotator cuff tear patterns also become easier to explain when you can trace the infraspinatus tendon’s course to the greater tubercle and relate it to posterior deltoid splitting approaches and arthroscopic portals. Use this artwork in gross anatomy and kinesiology modules on the shoulder girdle, in orthopaedic and sports medicine teaching files covering rotator cuff examination (external rotation lag sign, resisted external rotation), and in patient education pieces that need a clear posterior map of scapular and upper back musculature. Anatomical accuracy verified by SciePro's Medical Advisory Board.