Flexor digiti minimi of foot

The flexor digiti minimi muscle of the foot is a small intrinsic muscle located in the third (deep) layer of the plantar aspect of the foot. It originates from the base of the fifth metatarsal and the sheath of the fibularis longus tendon, and inserts into the lateral side of the base of the proximal phalanx of the fifth toe. Its function is to flex the proximal phalanx of the fifth digit at the metatarsophalangeal joint. This muscle is innervated by the superficial branch of the lateral plantar nerve, a branch of the tibial nerve. The flexor digiti minimi is distinct from the abductor digiti minimi, which lies more superficially and laterally.

Origin: Base of the fifth metatarsal bone, sheath of the tendon of fibularis (peroneus) longus

Insertion: Lateral side of the base of the proximal phalanx of the fifth toe

Nerve: Superficial branch of the lateral plantar nerve (S2–S3)

Blood supply: Lateral plantar artery

Action: Flex and adduct the fifth toe

Antagonist: Abductor digiti minimi muscle

Gray's description: The Flexor digiti minimi brevis (Flexor digiti quinti brevis) lies under the metatarsal bone of the little toe, and resembles one of the Interossei. It arises from the base of the fifth metatarsal bone, and from the sheath of the Peronaeus longus; its tendon is inserted into the lateral side of the base of the first phalanx of the fifth toe. Occasionally a few of the deeper fibers are inserted into the lateral part of the distal half of the fifth metatarsal bone; these are described by some as a distinct muscle, the Opponens digiti minimi of foot (Opponens digiti quinti.).