flexor pollicis brevis

Origin

• superficial head: flexor retinaculum of wrist
• deep head: ulnar side of 1st metacarpal

Insertion

base of proximal phalanx of thumb

Action

flexes proximal phalanx of thumb

Innervation

• superficial head: median nerve
• deep head: deep branch of ulnar nerve

More general terms

• skeletal muscle (voluntary muscle)