Muscle
Extensor hallucis longus
Long extensor connecting the fibula to the great toe
High-yield
Great-toe extension is commonly used when examining the L5 motor pathway. The same movement also depends on the peripheral deep fibular nerve and an intact extensor tendon.
Overview
Extensor hallucis longus lies between the other anterior leg extensors and sends a tendon toward the big toe. Reaching its distal phalanx lets the muscle extend the toe's end joint as well as assist ankle movement.
Reference facts
- Origin
- Middle anterior/medial fibular surface and adjacent interosseous membrane
- Insertion
- Dorsal base of the great toe's distal phalanx; accessory tendon slips may occur
- Action
- Extends the great toe at its joints, assists dorsiflexion and can contribute to inversion
- Innervation
- Deep fibular nerve; L5 is the commonly emphasized functional root
- Blood supply
- Anterior tibial arterial branches
Clinical correlation
Weak great-toe extension can occur with L5 nerve-root disease, a fibular nerve lesion or a local tendon problem. A clinician interprets it with other strength, sensation and reflex findings rather than using it as a stand-alone test.
Frequently asked questions
What does the extensor hallucis longus do?
The extensor hallucis longus extends the great toe at its joints, assists dorsiflexion and can contribute to inversion.
What nerve innervates the extensor hallucis longus?
Deep fibular nerve; L5 is the commonly emphasized functional root.
Where does the extensor hallucis longus attach?
Origin: Middle anterior/medial fibular surface and adjacent interosseous membrane. Insertion: Dorsal base of the great toe's distal phalanx; accessory tendon slips may occur.
What is the blood supply of the extensor hallucis longus?
Anterior tibial arterial branches.