Pectoralis Minor

Description

Arising from the anterior surfaces of ribs 3 to 5 near their costal cartilages, the pectoralis minor courses superolaterally to its insertion on the coracoid process of the scapula, lying deep to pectoralis major on the anterior thoracic wall of an adult male. The clavicle sits superior to the muscle belly, while the scapula and glenohumeral region occupy the lateral margin of the field, with the ribcage forming the medial and inferior bony backdrop. An anterolateral viewpoint makes the muscle’s triangular profile and fiber direction easy to follow from the thorax to the shoulder girdle. Depth relationships are clear. Clinically, pectoralis minor is a frequent suspect in anterior shoulder girdle pain and neurovascular symptoms because the cords of the brachial plexus and the axillary artery pass deep to it as they transition beneath the coracoid into the axilla. Tightness or hypertrophy can contribute to pectoralis minor syndrome, a form of thoracic outlet compression that often presents with paresthesias provoked by shoulder protraction and overhead activity. It also acts as a practical landmark during axillary dissection and coracoid-based approaches, where its medial border and insertion help orient the surgeon to the underlying axillary vessels. Small muscle. Big consequences. Use this asset for gross anatomy teaching on the pectoral region, kinesiology modules on scapulothoracic mechanics (protraction, downward rotation, and anterior tilt), and for clinical graphics discussing thoracic outlet syndromes, shoulder protraction posture, or coracoid and axillary surgical anatomy in textbooks, journals, and patient education. Anatomical accuracy verified by SciePro's Medical Advisory Board.