For the muscle of the foot, see Flexor digiti quinti brevis muscle (foot)

The flexor digiti minimi brevis is a muscle in the hand that flexes the little finger. It lies in the same plane as the abductor digiti minimi, on its radial side.

Structure

It arises from the convex surface of the hamulus of the hamate bone

Hamate bone

The hamate bone is a bone in the human hand that may be readily distinguished by its wedge-shaped form, and the hook-like process which projects from its volar surface. It is situated at the medial and lower angle of the carpus, with its base downward, resting on the fourth and fifth metacarpal...

, and the palmar surface of the flexor retinaculum of the hand

Flexor retinaculum of the hand

The flexor retinaculum is a strong, fibrous band that arches over the carpus, converting the deep groove on the front of the carpal bones into a tunnel, the carpal tunnel, through which the Flexor tendons of the digits and the median nerve pass.It is attached, medially, to the pisiform and the...

, and is inserted into the ulnar side of the base of the first phalanx of the little finger

Little finger

The little finger, often called the pinky in American English, pinkie in Scottish English , or small finger in medicine, is the most ulnar and usually smallest finger of the human hand, opposite the thumb, next to the ring finger.-Muscles:There are four muscles that...

.

It is separated from the abductor digiti minimi, at its origin, by the deep branches of the ulnar artery

Ulnar artery

The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspect of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery...

 and the ulnar nerve

Ulnar nerve

In human anatomy, the ulnar nerve is a nerve which runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest unprotected nerve in the human body , so injury is common...

. This muscle is sometimes not present; in these cases, the abductor digiti minimi is usually larger than normal.

It is a hypothenar muscle.

Innervation

The flexor digiti minimi brevis, like other hypothenar muscles, is innervated by the deep branch of the ulnar nerve

Ulnar nerve

In human anatomy, the ulnar nerve is a nerve which runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest unprotected nerve in the human body , so injury is common...

.

Etymology

The name of this muscle is Latin for the 'short flexor of the little finger'. Note that brevis is usually included to differentiate it from a longus muscle of the same name. The flexor digiti minimi longus, however, is not found in the typical human, but instead is a rare anatomical variation.