Origin: Flexor retinaculum and tubercles of scaphoid and trapezium.

Insertion: Lat. side of 1st metacarpal.

Action: Opposition of thumb- draws 1st metacarpal to center of palm and rotates it medially.

Inervation: Recurrent branch of median n. (C8, T1).

Origin: Flexor retinaculum and tubercles of scaphoid and trapezium.

Insertion: Lat. side base of proximal phalanx of thumb.

Action: ABD thumb; helps with opposition.

Inervation: Recurrent branch of median n. (C8, T1)

Origin:  Superficial and deep head- Flexor retinaculum and tubercles of scaphoid and trapezium.

Insertion: Lat. side base of proximal phalanx of thumb.

Action: Flexes thumb.

Inervation: Recurrent branch of median n. (C8, T1)

Origin: Oblique head- bases of 2nd and 3rd metacarpals, capitate and adjacent carpals.

           Transverse head- ant. surface of shaft of 3rd metacarpal.

Insertion: Med. side base of proximal phalanx of thumb.

Action: ADD of thumb.

Inervation: Deep branch of ulnar n. (C8, T1)