Opponens digiti minimi of hand

The opponens digiti minimi (Latin: musculus opponens digiti minimi) is a small triangular-shaped muscle located on the ulnar side of the hand. It is one of the muscles of the little finger, also known as one of the hypothenar muscles. Together with the abductor digiti minimi and flexor digiti minimi brevis, the opponens digiti minimi forms the hypothenar eminence. The opponens digiti minimi stretches between the hamate bone and the fifth metacarpal bone. It is situated medially to the flexor digiti minimi brevis and inferior to the abductor digiti minimi of the hand.

Origin

The opponens digiti minimi muscle originates from the flexor retinaculum and the hook of the hamate bone.

Insertion

The opponens digiti minimi inserts on the medial (ulnar) aspect of the fifth metacarpal bone.

Action

The primary function of the opponens digiti minimi muscle is the opposition of the little finger.

Innervation

The opponens digiti minimi is innervated by the deep branch of the ulnar nerve that arises from the brachial plexus (C8, T1).

Blood supply

The opponens digiti minimi muscle receives arterial blood supply from the deep palmar arch and artery. The deep palmar arch is primarily formed by the radial artery, while the deep palmar artery is a branch of the ulnar artery.