Origin: Distal anterior surface of the fibula
Insertion: Dorsal surface of metatarsal 5
Artery: Anterior tibial artery
Nerve: Deep fibular nerve
Action: Dorsi flexes and everts foot
The Peronaeus tertius is a part of the Extensor digitorum longus, and might be described as its fifth tendon. The fibers belonging to this tendon arise from the lower third or more of the anterior surface of the fibula; from the lower part of the interosseous membrane; and from an intermuscular septum between it and the Peronaeus brevis. The tendon, after passing under the transverse and cruciate crural ligaments in the same canal as the Extensor digitorum longus, is inserted into the dorsal surface of the base of the metatarsal bone of the little toe. This muscle is sometimes wanting.