Extensor digitorum

Anatomy

Origin:
Lateral epicondyle of humerus via the common extensor tendon and adjacent intermuscular septum.

Insertion:
Through separate tendons inserting into extensor hoods on dorsal surface of middle and distal phalanges of the four fingers.

Key Relations:
One of the two muscles in the intermediate posterior compartment of the forearm.

Functions

-Extension of four fingers at the metacarpophalangeal joints.
-Extension of interphalangeal joints of the four fingers.
-Helps extend hand at wrist.

Supply

Nerve Supply:
Posterior interosseous nerve (C7,C8) (continuation of deep branch of the radial nerve).

Blood Supply:
Posterior interosseous artery.

Clinical

Is affected in radial nerve palsy.

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