Corpus: Adductor pollicis muscle

Origin

The muscle comprises two heads with distinct points of origin. The oblique head, running obliquely to the metacarpal bones, originates at the capitate bone, the base of the metacarpal muscle II and III, and the ligamentous structures on the palmar side of the carpus. The transverse head has a broad-based origin from the body of metacarpal bone III and runs nearly perpendicular to the metacarpal bones.

Insertion

The short tendon of the muscle traverses the small sesamoid bone to the base of the proximal phalanx of the thumb (digit I).

The adductor pollicis muscle is innervated by the deep branch of the ulnar nerve from the brachial plexus (segments: C8 and Th1).

The princeps pollicis artery, a branch stemming from the radial artery, provides the adductor pollicis muscle with its blood supply. Additional vascular support comes from the deep palmar arch. Venous drainage is facilitated through the venous networks within the palm.

The adductor pollicis muscle is involved in the adduction and opposition movement of the thumb.

In the event of ulnar nerve dysfunction, the resulting paralysis of the adductor pollicis muscle can manifest as a negative Schaeffer's Test and may potentially give rise to the presence of Froment's sign.