Name
Pronunciation
(ad-DUK-tor POL-uh-sus)
Origin/Proximal Attachment
Transverse Head: 3rd metacarpal Oblique Head: base of 1st-3rd metacarpals; floor of carpal tunnel
Insertion/Distal Attachment
Medial aspect of base of proximal phalanx; medial sesamoid at MCP
Action/Relevance
Adducts thumbMay assist to flex thumb (at MCP joint)
Innervation
Ulnar nerve - deep branch (C8, T1)
Notes
Muscle for adduction and opposition of the thumb. Origin: oblique head: the capitate and the bases of the second and third metacarpals. Transverse head: palmar aspect of third metacarpal. Insertion: ulnar side of the base of the proximal phalanx of the thumb.