[Location ] Localized in the erect sitting position or supine position, on the dorsum of the foot, in the depression proximal to the first metatarsal space. (Fig.34)
 
[Regional Anatomy] Skin→subcutaneous tissue→between the tendons of extensor hallucis longus and extensor digitorum longus→the lateral aspect of extensor hallucis brevis tendon→the first dorsal interossei. Superficial layer, the dorsal venous network of the foot, the medial dorsal cutaneous nerve of the foot; deep layer, the deep peroneal nerve, and the first dorsal digital artery and vein.