Flexor hallucis brevis muscle Flexor hallucis brevis muscle The Flexor hallucis brevis is a muscle of the foot that flexes the big toe. It 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 which is attached to that bone. It divides in front into two portions, which are inserted into the medial and lateral sides of the base of the first phalanx of the great toe, a sesamoid bone being present in each tendon at its
Fourth metatarsal bone on the lateral side a single facet, for articulation with the fifth metatarsal. The head or anterior extremity articulates with the fourth proximal phalanx, the first bone in the fourth toe. The third and fourth dorsal interossei muscles attaches to the fourth metatarsal bone. The third dorsal interossei from the medial side of the bone and the fourth dorsal interossei from the lateral side. The function of the muscle is to spread the toes. The second Plantar interossei muscle originates from the medial side of the base and shaft of the fourth metatarsal. The function of the muscle is to