Interossei of the Hand, Anterior View

Description

Centered on the deep palmar compartment, the palmar interossei occupy the volar surfaces of the metacarpals and course distally to join the extensor expansion and the bases of the proximal phalanges, while the dorsal interossei fill the intermetacarpal spaces more dorsally but remain appreciable from an anterior dissection. Flexor digitorum superficialis and profundus tendons run superficially into the fibrous digital sheaths, with the lumbricals arising from the profundus tendons on the radial sides and passing volar to the metacarpophalangeal joints. Metacarpals, proximal phalanges, and the metacarpophalangeal joint lines provide the bony scaffold, with the interossei lying deep to the palmar aponeurosis and adjacent to the deep transverse metacarpal ligament. Deep anatomy, tight quarters. Functionally, this anterior perspective clarifies how interossei flex the metacarpophalangeal joints while extending the interphalangeal joints via the extensor hood, and how the palmar interossei adduct digits toward the third ray while the dorsal interossei abduct away from it. Denervation of these muscles from a lesion of the deep branch of the ulnar nerve at Guyon canal produces loss of finger abduction and adduction and contributes to ulnar clawing, a pattern you can map directly onto the tendinous relationships shown here. The same anatomy explains why intrinsic tightness and metacarpophalangeal contracture alter balance across the interphalangeal joints after trauma or prolonged immobilization. Use this illustration in gross anatomy and hand surgery teaching to accompany intrinsic muscle dissection, ulnar nerve lesion localization, and tendon balance discussions in the context of claw hand and lumbrical plus deformity. It also suits atlases and journal figures addressing metacarpal fractures, deep palmar space approaches, or postoperative therapy concepts such as intrinsic stretching and metacarpophalangeal positioning. Anatomical accuracy verified by SciePro's Medical Advisory Board.