Teres Minor Muscle Under the Skin

Description

Posterolateral shoulder anatomy is rendered with the skin, subcutaneous tissue, and deep fascia kept semi-transparent to expose the rotator cuff layer. Teres minor sits along the lateral border of the scapula, immediately inferior to infraspinatus and superior to teres major, then courses laterally toward its insertion on the inferior facet of the greater tubercle of the humerus. Posterior deltoid fibers cap the cuff superficially, while trapezius occupies the more superior medial back and latissimus dorsi sweeps inferomedially, framing the scapular region. A slender highlighted band near the humeral head plausibly marks the cuff tendon footprint or a bursal plane used to separate deltoid from underlying rotator cuff. Teres minor matters because it is the posterior cuff muscle most directly tested when you want external rotation strength in abduction, the Hornblower sign, and it often behaves differently from infraspinatus in massive cuff tears. At the surgical neck of the humerus, the quadrangular space lies just anterior to teres minor (bounded by teres minor superiorly and teres major inferiorly), transmitting the axillary nerve and posterior circumflex humeral artery, so denervation can present as teres minor atrophy with posterior shoulder pain and weak external rotation. That relationship also informs safe dissection planes during a posterior approach to the shoulder and when decompressing suspected quadrilateral space syndrome. Use this asset for rotator cuff teaching in gross anatomy and sports medicine courses, for orthopaedic or radiology texts discussing posterior cuff tears and fatty infiltration patterns, and for operative planning figures that explain deltoid-splitting exposure and the nearby axillary nerve corridor. Anatomical accuracy verified by SciePro's Medical Advisory Board.