Extensor hallucis longus is one of the anterior leg muscles. It arises from the:
- middle of the anterior surface of the fibula
- interosseous membrane
It inserts into the dorsal side of the base of the distal phalanx of the great toe.
It has many actions:
- extension of great toe
- dorsiflexes foot at the ankle
- inverts the foot at the ankle
Extensor hallucis longus is innervated by the deep peroneal nerve (L5,S1).
It provides a means of testing the L5 and S1 nerve roots during the neurological examination. The patient is requested to 'pull the big toe back towards you' (dorsiflex) while the examiner resists this with forced plantarflexion.