Extensor Hallucis Brevis Under the Skin, Lateral View

Description

Along the dorsolateral foot, the extensor hallucis brevis (often described with extensor digitorum brevis as the extensor digitorum brevis pedis complex) lies immediately deep to the skin and superficial fascia, arising from the superolateral calcaneus near the sinus tarsi and coursing anteriorly toward the hallux. Its muscle belly sits lateral to the extensor hallucis longus tendon on the dorsum of the foot, and its tendon passes distally to blend with the dorsal expansion at the base of the proximal phalanx of the great toe. Adjacent tarsal elements are presented in profile, including the talus superiorly, the calcaneus posteriorly, and the navicular and cuboid anteriorly, with the cuneiforms and metatarsals aligned distally. Joint lines are delineated at the subtalar, talonavicular, and calcaneocuboid regions. A lateral perspective on extensor hallucis brevis helps when teaching the layered anatomy of the dorsal midfoot because the muscle forms a palpable mound anterolateral to the ankle that can confuse surface mapping of extensor tendons during exam. It also frames common operative corridors, including sinus tarsi and anterolateral ankle arthroscopy portals, where the extensor digitorum brevis and extensor hallucis brevis may be split or reflected to access the subtalar joint and lateral talar neck. Compression or traction of the deep fibular (peroneal) nerve branches on the dorsum, and iatrogenic injury to dorsal cutaneous nerves during incisions over the tarsus, become easier to explain with the skin overlay kept in register. Clear landmarks matter. Use this asset in lower limb anatomy labs, podiatry and orthopaedic teaching files, and surgical atlas figures discussing dorsal approaches to the talus, calcaneus, and midtarsal joints, as well as clinical diagrams for extensor tendinopathy or post-traumatic dorsal foot pain. Anatomical accuracy verified by SciePro's Medical Advisory Board.