Flexor hallucis brevis muscle

The flexor hallicus brevis m. consists of two heads: medial and lateral. Both work to flex the big toe and are located deep to the tendon of the flexor digitorum longus m.

Action: Flexes hallux

Innervation: Medial plantar 

Origin: Cuboid, lateral cuneiform

Insertion: Proximal phalanx of hallux