Fibularis Tertius - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The fibularis tertius is a muscle in the anterior compartment of the leg. It is an extension of the distal part of the extensor digitorum longus muscle and is not always present. Attachments: Originates with the extensor digitorum longus from the medial surface of the fibula. Its tendon descends onto the dorsal surface of the foot and attaches to the fifth metatarsal. Actions: Eversion and dorsiflexion of the foot. Innervation: Deep fibular nerve. Blood supply: Anterior tibial artery By TeachMeSeries Ltd (2026) Fig 1The muscles of the anterior leg. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Frequent questions What is the fibularis tertius muscle? The fibularis tertius is a muscle located in the anterior compartment of the leg, acting as an extension of the distal part of the extensor digitorum longus. It plays a role in foot movement and is not consistently present in all individuals. Where does the fibularis tertius originate? The fibularis tertius originates from the medial surface of the fibula, alongside the extensor digitorum longus muscle. This anatomical connection is crucial for its function and role in foot mechanics. What are the primary actions of the fibularis tertius? The primary actions of the fibularis tertius include eversion and dorsiflexion of the foot. These movements are essential for various activities such as walking and maintaining balance. Which nerve innervates the fibularis tertius? The fibularis tertius is innervated by the deep fibular nerve. This nerve supply is vital for the muscle's function in foot movement. What is the blood supply for the fibularis tertius? The fibularis tertius receives its blood supply from the anterior tibial artery. This vascular connection ensures that the muscle gets the necessary nutrients and oxygen for its activities. Rate This Article