Extensor pollicis brevis :-
Muscle details :-
the extensor pollicis brevis is a skeletal muscle on the dorsal side of the forearm. It lies on the medial side of, and is closely connected with, the abductor pollicis longus.
posterior surface of shafts of radius .
base of proximal phalanx of thump .
Nerve supply :-
deep branch of radial nerve .
extends metacarpophalangeal joint of thumb .