Muscle
Fibularis longus
Lateral leg muscle whose tendon crosses beneath the foot
High-yield
The route across the sole helps support the foot's transverse arch and first ray. It works with fibularis brevis in eversion, but its final attachment is on the medial side of the foot.
Overview
Fibularis longus descends along the outer leg, passes behind the lateral malleolus and turns under the cuboid. Its tendon then crosses the sole to attach near the medial cuneiform and first metatarsal.
Reference facts
- Origin
- Fibular head and upper lateral shaft, with adjacent intermuscular septa
- Insertion
- Plantar aspect of the medial cuneiform and base of the first metatarsal
- Action
- Everts the foot, assists plantarflexion and supports the transverse arch and medial forefoot
- Innervation
- Mainly the superficial fibular nerve, conventionally L5-S2; additional nerve branches are described
- Blood supply
- Fibular and anterior tibial muscular branches
Clinical correlation
Injury to the superior fibular retinaculum can let the tendons shift out of their groove behind the ankle. Painful snapping can also occur from movement between the tendons while that retaining band remains intact.
Frequently asked questions
What does the fibularis longus do?
The fibularis longus everts the foot, assists plantarflexion and supports the transverse arch and medial forefoot.
What nerve innervates the fibularis longus?
Mainly the superficial fibular nerve, conventionally L5-S2; additional nerve branches are described.
Where does the fibularis longus attach?
The fibularis longus originates from the fibular head and upper lateral shaft, with adjacent intermuscular septa and inserts on the plantar aspect of the medial cuneiform and base of the first metatarsal.
What is the blood supply of the fibularis longus?
The fibularis longus is supplied by the fibular and anterior tibial muscular branches.