Full Peroneus Tertius Muscle Description
[Continued from above] . . . includes the extensor digitorum longus.
The deep fibular nerve activates the peroneus tertius muscle. This is not the case for the other peroneal muscles. The superficial fibular nerve activates them. This is because the peroneus tertius is part of the anterior compartment.
The peroneus tertius muscle functions to flip the foot at the ankle joint and has weak dorsiflexion of the ankle joint.