Overview
Its belly lies caudolateral to the extensor carpi radialis. Its tendon crosses the dorsal surface of the carpus and splits into four, one for each weight-bearing digit.
Origin
Lateral epicondyle of the humerus.
Insertion
Extensor processes of the distal phalanges of digits II to V.
Action
Extends the digital joints and the carpus.
Innervation
Radial nerve (n. radialis).
Clinical relevance
With a radial nerve injury the dog cannot extend its digits and knuckles over onto the dorsum of the paw.