The flexor digiti minimi brevis is a hypothenar muscle in the hand that flexes the little finger (digit V) at the metacarpophalangeal joint.

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

The spinal roots of C8 and T1 then merge to form the lower trunk, anterior division, medial cord, and finally produce the ulnar nerve.

The flexor digiti minimi brevis flexes the little finger at the metacarpophalangeal joint.

The flexor digiti minimi longus, however, is not found in the typical human, but instead is a rare anatomical variation.