Anterior Perspective of the Muscles of the Lower Hand Under the Skin

Description

Across the palmar (anterior) surface of the male hand, the thenar eminence lies radial and proximal to the thumb metacarpophalangeal joint, formed by abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis beneath the palmar skin and fat. Ulnar and slightly distal, the hypothenar eminence contains abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, and the superficial palmaris brevis overlying the ulnar neurovascular bundle. Distally, the long flexor tendons, flexor digitorum superficialis and flexor digitorum profundus to digits 2 through 5 and flexor pollicis longus to the thumb, course within fibrous digital sheaths and pulley systems toward the middle and distal phalanges, while lumbricals arise from the profundus tendons on the radial sides and run toward the extensor expansions. Fine stabilizers are indicated by palmar interossei and joint ligaments at the metacarpophalangeal and interphalangeal levels. Palmar anatomy is where function and pathology collide. Median nerve compression beneath the flexor retinaculum (transverse carpal ligament) produces carpal tunnel syndrome with thenar weakness and loss of thumb opposition, a pattern best appreciated when you can compare thenar bulk to the ulnar-sided hypothenar mass. Dupuytren disease, arising from the palmar aponeurosis and pretendinous bands, draws the ring and small fingers into flexion, and the relationship of those fascial cords to the flexor tendons and digital pulleys explains why contracture can progress without tendon shortening. Small structures, big consequences. Use this artwork in gross anatomy and hand anatomy teaching to clarify intrinsic muscle groups under the palmar integument and to map flexor tendon trajectories before cadaveric dissection. It also suits operative texts and clinical education on carpal tunnel release, trigger finger (A1 pulley) injection, and flexor tendon repair zones in the palm and digits. Anatomical accuracy verified by SciePro's Medical Advisory Board.