Pectoralis Minor

Description

Shown on the left anterior thoracic wall, the pectoralis minor lies deep to pectoralis major and hugs the convexity of the rib cage as it runs superolaterally from the anterior surfaces of ribs 3 to 5 (near their costal cartilages) to the coracoid process of the scapula. The adjacent bony landmarks remain readable, including the sternum medially, the rib arcs laterally, and the scapula and proximal humerus of the shoulder girdle superiorly and laterally. Cervical and upper thoracic vertebrae provide posterior midline context while keeping attention on the anterior chest. Pectoralis minor matters because it is both a scapular stabilizer and a landmark for axillary anatomy: its medial and lateral borders relate to the axillary artery (classically described in parts by the muscle’s position), and the clavipectoral fascia investing it forms a layer traversed in infraclavicular approaches. Anterior shoulder pain and paresthesia can follow pectoralis minor tightness or hypertrophy, which may contribute to neurovascular compression in pectoralis minor syndrome (a variant of thoracic outlet), and the rib to coracoid fiber direction helps explain how excessive protraction and anterior tilt of the scapula can be driven by this muscle. Small muscle, big implications. Use this asset in gross anatomy teaching to distinguish pectoralis minor from pectoralis major and serratus anterior, in orthopedic or sports medicine materials discussing scapular dyskinesis, and in surgical education referencing axillary exposure and infraclavicular regional anesthesia pathways. Anatomical accuracy verified by SciePro's Medical Advisory Board.