"origin: mainly from the flexor retinaculum"
"insertion: its medial fibres are attached by a thin, flat tendon to the radial side of the proximal phalangeal base in the pollex and lateral fibres join the pollicial dorsal digital expansion"
"innervation: lateral branch of median nerve (C8 and T1)"
"action: abducts the thumb and medially rotates it at the carpometacarpal and metacarpophalangeal joints"
Expected headings
"Summary"