Extensor Digitorum Muscle, Posterior View

Description

Dorsal hand and wrist anatomy is presented in posterior view, with the extensor digitorum muscle giving rise to multiple tendons that pass distally across the dorsum of the carpus toward digits II to V. Proximally, the extensor tendons course centrally on the posterior forearm and continue under the extensor retinaculum at the wrist, then fan out over the metacarpals toward the phalanges. Carpals, metacarpals, and phalanges are rendered in situ to anchor tendon position and line of pull. Clear fiber direction and tendon caliber are emphasized. Posterior visualization of extensor digitorum matters because it is the main extrinsic extensor for the medial four digits and a key contributor to the extensor expansion (dorsal digital hood), where tendon balance determines coordinated MCP extension with IP extension. Small disruptions here have outsized consequences. This is the perspective you want when teaching mallet finger (terminal extensor tendon avulsion at the distal phalanx), boutonniere deformity (central slip failure), and sagittal band rupture with extensor tendon subluxation at the metacarpophalangeal joint, injuries often assessed and repaired with the dorsum exposed. Common use cases include upper limb anatomy labs, hand therapy and sports medicine teaching materials, and operative manuals covering dorsal approaches to the wrist and digits, including compartment-based discussions of extensor tendon tenosynovitis and post-traumatic adhesions. It also fits radiology and ultrasound correlation when orienting learners to dorsal tendon groups as they traverse the wrist. Anatomical accuracy verified by SciePro's Medical Advisory Board.