Abductor Digiti Minimi, Anterior View

Description

Arising from the pisiform and tendon of flexor carpi ulnaris, the abductor digiti minimi forms the superficial bulk of the hypothenar eminence on the ulnar side of the palm, running distally to the ulnar aspect of the base of the proximal phalanx of the little finger and blending with the extensor expansion. Medial to it lies the ulnar border of the hand, while the flexor retinaculum and palmar aponeurosis sit more proximally and centrally, respectively. Deep to the muscle belly you would expect the hypothenar compartment to transition toward flexor digiti minimi brevis and opponens digiti minimi, with the pisohamate ligament and hook of hamate positioned deep and slightly radial. Nearby, the ulnar artery and ulnar nerve enter the palm through Guyon canal, then split into superficial and deep branches adjacent to the hypothenar musculature. An anterior perspective on abductor digiti minimi matters because it frames the ulnar-sided landmarks used when evaluating intrinsic muscle weakness and sensory symptoms in the ring and small fingers. Compression of the ulnar nerve in Guyon canal, often from a ganglion cyst or repetitive handlebar pressure, can denervate the hypothenar muscles and produce visible flattening of this eminence with impaired little-finger abduction. Hand surgeons also reference this corridor during ulnar tunnel decompression and when planning hypothenar-based flaps, where preserving the ulnar artery and the deep motor branch is nonnegotiable. Small muscle, big consequences. Use this asset for gross anatomy lab manuals covering the intrinsic hand muscles, for hand therapy texts illustrating hypothenar function in grip and pinch patterns, and for clinical teaching slides on ulnar neuropathy localization at the wrist versus cubital tunnel. It also fits operative anatomy chapters discussing Guyon canal release and hypothenar flap design. Anatomical accuracy verified by SciePro's Medical Advisory Board.