Origin:
OBLIQUE HEAD: palmar surfaces of the Trapezoid, the Trapezium and Capitate as well as the bases of the Index and Middle metacarpals
TRANSVERSE HEAD: palmar surface of the shaft of the Middle metacarpal
Insertion: The palmar ulnar base of the Thumb Proximal Phalanx, the Thumb Ulnar MCP Sesamoid, and the Thumb extensor mechanism
Function: radially adducts the thumb basal joint along with other muscles which radially adduct the basal joint, and extends the thumb interphalangeal Joint
Nerve: Motor Branch of Ulnar Nerve
Artery: Deep Palmar Arch