Extensor hallucis brevis muscle

The extensor hallucis brevis is a muscle on the top of the foot that helps to extend the big toe.

Structure
The extensor hallucis brevis is essentially the medial part of the extensor digitorum brevis muscle. Some physiologists have debated whether these two muscles are distinct entities.

The extensor hallucis brevis arises from the calcaneus and inserts on the proximal phalanx of the digit 1 (the big toe).

Innervation
The extensor hallucis brevis is innervated by the deep fibular nerve (deep peroneal nerve).

Action
The extensor hallucis brevis helps to extend the big toe.