The peroneus tertius (fibularis tertius) is one of the muscles within the anterior compartment of the leg. Collectively, the muscles of the anterior compartment act to extend the toes, dorsiflex the ankle and invert the foot.
The leg is comprised of anterior, lateral and posterior compartments.
The anterior compartment consists of four muscles:
Origin
- Distal part of medial fibula
Insertion
- Dorsomedial surface of base of 5th metatarsal
Action
- Dorsiflexion of foot
- Eversion of foot
Innervation
- Deep fibular nerve: L5,S1
Blood Supply
- Anterior tibial artery