Name

# Opponens Digiti Minimi

Pronunciation

(o-PONE-ens DIG-i-ti MIN-i-me)

Origin/Proximal Attachment

Distal border of flexor retinaculum; hook of hamate

Insertion/Distal Attachment

Medial aspect of 5th metacarpal

Action/Relevance

Opposes 5th digit with thumb Assists to ‘cup’ the palm

Innervation

Ulnar nerve - deep branch (C8, T1)

Notes

Opponens digiti minimi is one of the hypothenar muscles. It lies deep to the flexor and abductor muscles.

It originates from the hook of the hamate bone of the wrist and the flexor retinaculum. It passes in an ulnar and distal direction to insert into the ulnar border of the shaft of the fifth metacarpal bone.

It is innervated by the deep branch of the ulnar nerve (C8,T1).

The action of opponens digiti minimi are to oppose the little finger to thumb by:

* flexion of the fifth metacarpal

* lateral rotation of the carpometacarpal joint of the fifth digit

* lateral rotation of the metacarpophalangeal joint of the fifth digit