Peroneus Tertius:The peroneus tertius (also identified as fibularis tertius) muscle is found in the lower limb.
Origin: The muscle originates from the lower third of the anterior surface of the fibula and the anterior intermuscular septum (within the extensor digitorum longus and the tibialis anterior muscles).
Insertion: Dorsal surface of the base of the fifth metatarsal bone.
Function: Acts with the extensor digitorum longus to dorsiflex, evert and abduct the foot.
Nerve Supply: Deep peroneal nerve