ABSTRACT
This chapter summarizes the typical presentations, comparative anatomy, variations, and anomalies for the muscles of the upper limb. Entries for the axial pectoral girdle muscles include five muscles typically present in humans, as well as seven muscles present only as variations or anomalies: rhomboideus occipitalis, rhomboideus tertius, pectoralis intermedius, subclavius posticus, levator claviculae, sternoscapularis, and supraclavicularis proprius. The pectoral girdle and arm muscles include 13 typically present muscles, as well as 18 muscles present only as variations or anomalies. These muscles are sternalis, dorsoepitrochlearis, panniculus carnosus, chondroepitrochlearis, sternoclavicularis, pectoralis quartus, pectorodorsalis, pectoralis minimus, costocoracoideus, tensor semivaginae articulationis humeroscapularis, infraclavicularis, costoclavicularis, Roos bands, subscapularis minor, levator tendinis musculi latissimus dorsi, coracobrachialis profundus, coracobrachialis longus, and epitrochleoanconeus. Entries for the anterior forearm muscles include eight typically present muscles, as well as Gantzer’s muscle, radiocarpus, and flexor carpi radialis brevis. The posterior forearm muscles section includes 12 typically present muscles, as well as extensor carpi radialis accessorius, ulnaris digiti quinti, extensor medii digiti, and extensor digitorum brevis manus. Entries for the muscles of the hand include 11 muscles typically present in humans, and only one muscle that presents as a variation or anomaly: contrahentes digitorum manus.
