Flexor digiti minimi of hand

At a glance

English

Flexor digiti minimi of hand

Latin (TA2)

Flexor digiti minimi manus

System

Muscle

Region

Upper limb

Side

Paired, left and right

About the flexor digiti minimi of hand

This short flexor belongs to the trio of muscles of the hypothenar eminence, the fleshy pad on the ulnar side of the palm. It lies alongside the abductor digiti minimi, on its radial side, and covers part of the opponens digiti minimi, which sits deeper.

It takes origin from the hook of the hamate and from the front of the nearby flexor retinaculum. The fibres pass down along the ulnar border of the palm and end in a short tendon that attaches, together with the abductor, to the little finger, on the ulnar edge of its proximal phalanx base. Between its origin and that of the abductor there is a small gap through which the ulnar nerve and artery send their deep branches on their way into the palm.

The muscle bends the knuckle joint of the little finger. It helps cup the palm, as when holding water in the hand, and adds to the grip of the ulnar side of the hand on a handle or racket. Like the other hypothenar muscles it is innervated by the deep ulnar branch. Its blood comes from the ulnar artery, mostly by its deep palmar branch.

In some hands the muscle is small, missing or fused with the abductor. Because the hook of the hamate anchors it, a fracture of the hook, seen in golfers and racket players, can give pain when the little finger is bent against resistance. Weakness of the muscle, with flattening of the hypothenar pad, points to damage of the ulnar nerve at the wrist or elbow.

Attachments, action and supply

Origin

Hook of the hamate and the adjacent flexor retinaculum.

Insertion

Little finger proximal phalanx, ulnar edge of its base.

Action

Bends the little finger at its knuckle joint and helps cup the palm.

Nerve supply

Ulnar nerve, deep branch (C8, T1).

Blood supply

Ulnar artery, chiefly its deep palmar branch.