Fibularis brevis
The shorter of the two everting muscles, attaching to the bony bump on the outer edge of your foot.
- Type
- Muscle
- Region
- Leg
- Standard name
- m. peroneus brevis
- Origin
- Lower two-thirds of the lateral surface of the fibula
- Insertion
- Tuberosity at the base of the fifth metatarsal
- Actions
- foot eversionankle plantarflexion
- Verify
- TA2 2653 TA98 A04.7.02.042
What it is
A shorter muscle lying underneath fibularis longus on the outer lower leg. Its tendon travels behind the outer ankle bone alongside the longus tendon, then continues forward to attach on the tuberosity at the base of the fifth metatarsal — the bump you can feel halfway along the outside edge of your foot.
Also called peroneus brevis, for the reasons set out in the fibularis longus record.
What it does
Everts the foot and assists plantarflexion, working with fibularis longus.
Unlike its longer partner it does not cross the sole, so it plays no part in supporting the arch. Its pull is a straightforward outward one on the edge of the foot.
What loads it
Eversion against resistance, and single-leg balance work.
What is commonly got wrong about it
Fifth metatarsal fractures and this tendon. A common injury is an avulsion fracture at the base of the fifth metatarsal — where the bone is pulled off at this tendon's attachment during an ankle roll. It is frequently mistaken for a sprain, because the mechanism is identical and so is the initial swelling. A foot injury that will not bear weight should be looked at rather than assumed.
That it is redundant given fibularis longus. They attach in different places and pull on different bones. The longus supports the arch; this one does not.