Flexor Hallucis Brevis

Origin

The flexor hallucis brevis muscle originates from the:

- plantar surface of the cuboid bone;

- plantar surface of the lateral cuneiform bone;

- tendon of the tibialis posterior muscle.

Insertion

The fibers of the flexor hallucis brevis muscle travel anteriorly and divide into two separate tendons. Both tendons contain a sesamoid bone and they insert onto the medial and lateral aspects of the base of the proximal phalanx of the great toe.

Key Features & Anatomical Relations

The flexor hallucis brevis muscle is located in the third layer of muscles that are found in the plantar part of the foot. It is a short skeletal muscle.

It is located:

- superior to the tendon of the flexor digitorum longus muscle;

- inferior to the first metatarsal bone;

- medial to the adductor hallucis muscle and the first lumbrical muscle of foot;

- lateral to the abductor hallucis muscle and the medial plantar nerve.

Actions & Testing

The flexor hallucis brevis muscle flexes the proximal phalanx at the metatarsophalangeal joint of the great toe. It can be tested by flexing the proximal phalanx of great toe at its metatarsophalangeal joint against resistance, while its interphalangeal joint is held in the extended position. This position prevents the flexor hallucis longus muscle from contracting (Standring, 2016).

References

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.