Name
Pronunciation
(FLEK-sur POL-uh-sus BREV-is)
Origin/Proximal Attachment
Distal border of flexor retinaculum & trapezium
Insertion/Distal Attachment
Base of proximal phalanx of thumb
+/- to lateral sesamoid bone at MCP joint
Action/Relevance
Flexes thumb (at MCP joint)
Innervation
Superficial Head: Median nerve - recurrent branch (C8, T1)
Deep Head: Ulnar nerve - deep branch (C8, T1)
Notes
Muscle for flexion and adduction of the thumb. Origin: flexor retinaculum, trapezium and trapezoid. Insertion: base of the proximal phalanx of hand of the thumb.