Extensor digitorum (left) (Musculus extensor digitorum)
Educational content only — not medical advice.
Anatomy
The central superficial posterior-compartment muscle: four tendons cross the wrist in the fourth dorsal compartment and fan into the extensor expansions over the proximal phalanges, distributing extension across all three finger joints.
Origin & insertion
Lateral epicondyle via the common extensor tendon and antebrachial fascia.
Action
Extends the proximal, middle and distal phalanges and the wrist; its middle-joint action is distinguished from the interossei in digital testing.
Innervation
Radial nerve — posterior interosseous branch (C7–C8).
Clinical notes
Zone-VI lacerations over the wrist are common in stab injuries; therapy splints adjacent fingers to stop tendon-bulk displacement, and expansion blockage makes the classic mallet finger.
Related structures
Educational references
FAQ
What is the role of the Extensor digitorum (left)?
The central superficial posterior-compartment muscle: four tendons cross the wrist in the fourth dorsal compartment and fan into the extensor expansions over the proximal phalanges, distributing extension across all three finger joints.
Why is the Extensor digitorum (left) clinically important?
Zone-VI lacerations over the wrist are common in stab injuries; therapy splints adjacent fingers to stop tendon-bulk displacement, and expansion blockage makes the classic mallet finger.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details