Extensor hallucis brevis
Extensor brevis hallucis
- Latin synonym: Musculus extensor hallucis brevis
- Synonym: Extensor hallucis brevis muscle
Definition
The extensor hallucis brevis is a small muscle located on the dorsum of the foot, sometimes considered as the medial part of the extensor digitorum brevis muscle*. It originates from the superolateral surface of the calcaneus and the adjacent inferior extensor retinaculum, and inserts via its tendon into the dorsal aspect of the base of the proximal phalanx of the hallux (great toe). Its primary function is to assist in extension of the metatarsophalangeal joint of the hallux. The muscle lies medial to the extensor digitorum brevis and is innervated by the deep peroneal (fibular) nerve.
Origin: Dorsal surface of calcaneus
Insertion: Proximal phalanx of big toe.
Nerve: Lateral terminal branch of deep fibular nerve (proximal sciatic branches S1,S2). Same innervation of Extensor Digitorum Brevis
Action: Extends the big toe.
*Some anatomists have debated whether these two muscles (extensor hallucis brevis and extensor digitorum brevis muscle) are distinct entities.
References
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
