Muscle
Flexor pollicis brevis
Thenar — flexes the thumb
High-yield
Thenar; superficial head median (recurrent branch), deep head often ulnar — a hand muscle with dual supply.
Overview
A thenar muscle that flexes the thumb; usually median but its deep head may be ulnar-innervated.
Reference facts
- Origin
Flexor retinaculum and trapezium (superficial head); trapezoid and capitate (deep head)
- Insertion
Lateral base of the proximal phalanx of the thumb
- Action
Flexes the thumb at the carpometacarpal and MCP joints
- Innervation
Recurrent branch of the median nerve (superficial head); deep branch of the ulnar nerve (deep head)
- Blood supply
Superficial palmar arch