Muscle
Fibularis tertius
Variable anterior-compartment muscle assisting foot eversion
High-yield
Its fibularis name does not place it in the lateral leg compartment. It belongs to the anterior compartment and receives the deep fibular nerve, whereas fibularis longus and brevis usually receive the superficial branch.
Overview
Fibularis tertius is closely linked to the lower part of extensor digitorum longus. Its tendon crosses the front of the ankle toward the fifth metatarsal, and the muscle can be absent as an anatomical variation.
Reference facts
- Origin
- Distal anterior/medial fibula, adjacent interosseous membrane and the extensor digitorum longus region
- Insertion
- Dorsal base of the fifth metatarsal, with variable attachment extent
- Action
- Assists ankle dorsiflexion and turns the sole outward in eversion
- Innervation
- Deep fibular nerve muscular branches
- Blood supply
- Branches of the anterior tibial artery
Frequently asked questions
What does the fibularis tertius do?
The fibularis tertius assists ankle dorsiflexion and turns the sole outward in eversion.
What nerve innervates the fibularis tertius?
Deep fibular nerve muscular branches.
Where does the fibularis tertius attach?
The fibularis tertius originates from the distal anterior/medial fibula, adjacent interosseous membrane and the extensor digitorum longus region and inserts on the dorsal base of the fifth metatarsal, with variable attachment extent.
What is the blood supply of the fibularis tertius?
Branches of the anterior tibial artery.