The flexor digiti minimi brevis arises from the hamulus of the
hamate bone and the palmar surface of the
flexor retinaculum of the hand. It is inserted into the medial side of the base of the proximal phalanx of digit V. It is separated from the
abductor digiti minimi, at its origin, by the deep branches of the
ulnar artery and the
ulnar nerve. The flexor digiti minimi brevis is sometimes not present; in these cases, the abductor digiti minimi is usually larger than normal. The flexor digiti minimi brevis is one of three muscles in the
hypothenar muscle group. These three muscles form the fleshy mass at the base of the little finger, and are solely concerned with the movement of digit V. The other two muscles that make up the hypothenar muscle group are the
abductor digiti minimi and the
opponens digiti minimi. In anatomical position from medial to lateral is the abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi. ==Innervation==