The fibularis tertius is a muscle located in the anterior compartment of the leg. It is an extension of the distal portion of the extensor digitorum longus muscle, though it is not always present in some individuals. Its attachments, actions, innervation, and blood supply are discussed below.
The fibularis tertius originates with the extensor digitorum longus, specifically from the medial surface of the fibula. The tendon then descends onto the dorsal surface of the foot, attaching to the fifth metatarsal.
The primary action of the fibularis tertius muscle is the eversion and dorsiflexion of the foot.
The deep fibular nerve is responsible for innervating the fibularis tertius muscle.
The anterior tibial artery is the primary blood supply of the fibularis tertius muscle.
Fig 1 illustrates the muscles of the anterior leg. In this figure, the location and attachments of the fibularis tertius are evident.
The fibularis tertius is a muscle located in the anterior compartment of the leg. It is an extension of the distal portion of the extensor digitorum longus muscle, though it is not always present in some individuals. Its attachments include the extensor digitorum longus from the medial surface of the fibula and the fifth metatarsal on the dorsal surface of the foot. Its primary action is the eversion and dorsiflexion of the foot, which is innervated by the deep fibular nerve and supplied by the anterior tibial artery. Fig 1 illustrates the muscles of the anterior leg, including the fibularis tertius.
