Flexor hallucis brevis muscle

Flexor hallucis brevis muscle arises, by a pointed tendinous process, from the medial part of the under surface of the cuboid bone, from the contiguous portion of the third cuneiform, and from the prolongation of the tendon of the tibialis posterior muscle which is attached to that bone.

Origin subject to considerable variation; it often receives fibers from the calcaneus or long plantar ligament.

Flexor hallucis brevis flexes the first metatarsophalangeal joint, or the big toe.

Sesamoid bones contained within the tendon of flexor hallucis brevis muscle may become damaged during exercise.

[1] This article incorporates text in the public domain from page 493 of the 20th edition of Gray's Anatomy (1918)

The flexor hallucis brevis is located just inferior to the foot and toe bones. As its name suggests, its contraction results in flexion of the big toe (hallux).