Extensor Hallucis Longus

Description

Running in the anterior compartment of the leg, the extensor hallucis longus (EHL) arises from the middle third of the fibula and adjacent interosseous membrane, positioned lateral to the tibial crest and medial to extensor digitorum longus. Its slender belly transitions to a long tendon that crosses the anterior ankle deep to the superior and inferior extensor retinacula, then tracks along the dorsum of the foot to the dorsal base of the distal phalanx of the hallux. Medially, the tibia provides the dominant bony contour; laterally, the fibula parallels it, with the interosseous membrane spanning between them. Distal landmarks include the talus and other tarsals, metatarsals, and phalanges, with articular cartilage highlighted at the knee and tibiotalar joints. A single muscle stands out. Great toe dorsiflexion is a focused neurologic and orthopedic sign, and EHL is the effector you grade when testing L5 motor function, often in the setting of lumbar radiculopathy or peroneal division sciatic neuropathy. The tendon’s course across the anterior ankle places it at risk in open lacerations and in surgical portals around the ankle and midfoot, and its muscle belly shares the tight fascial boundaries that make pain on passive hallux flexion a useful clue in anterior compartment syndrome. Close neighbors matter: the deep fibular (peroneal) nerve and anterior tibial artery run just deep to EHL, and their relationship helps explain combined weakness and dorsal first web space sensory loss after trauma or compression. Use this asset for lower limb anatomy teaching in gross anatomy and kinesiology, for exam-prep figures illustrating ankle dorsiflexion and hallux extension, or for clinical education materials on L5 myotome testing, anterior compartment syndrome, and EHL tendon injury and repair. It also fits well in orthopedic and sports medicine publications discussing gait mechanics and toe-off dysfunction. Anatomical accuracy verified by SciePro's Medical Advisory Board.