Action.

Muscle.

Origin.

Insertion.

Nerve-supply.

Flexion

Flexor longus pollicis

See Wrist-Joint

Flexor brevis pollicis

1. Radial half lower border anterior annular ligament and the ridge on the trapezium

Radial side base of first phalanx

Median

2. Ulnar side of base of first metacarpal

Ulnar side of base of first phalanx

Ulnar

Abductor brevis pollicis

From the tubercle of the scaphoid, the ridge of the trapezium, the radial part of the anterior surface of the annular ligament

The radial side of the base of the first phalanx and the capsule of the joint

Median

Opponens pollicis

From the ridge on the trapezium and the anterior surface of the annular ligament

The whole of the radial border and the radial half of the palmar surface of the first metacarpal

Median

Adductor obliquus pollicis

From the palmar surfaces of the os trapezium and trapezoid, the OS magnum and bases of the second third, and fourth metacarpals

The ulnar side of the base of the first, phalanx

Ulnar

Adductor trans versus pollicis

From the lower two-thirds of the median ridge on the palmar surface of the third metacarpal

The ulnar side of the base of the first phalanx

Ulnar

Exten-sion

Abductor longus polliois

See Wrist-Joint

Extensor longus pollicis

See Wrist-Joint

Extensor brovis pollicis

See Wrist-Joint

Adduction

Adductor obliquus pollicis

See Flexion

Adductor trans-versus pollicis

See Flexion

Flexor brevis pollicis

See Flexion

Opponens pollicis

See Flexion

First dorsal interosseous

From the adjacent sides of the first and second metacarpal bones

The radial side of the index - linger on the dorsal expansion of the extensor tendon, the capsule of the metacarpo- phalangeal joint and the side of the first phalanx

Ulnar

Abduc-tion

Abductor brevis pollicis

See Flexion

Abductor longus pollicis

See Wrist-Joint

Extensors of thumb

See Wrist-Joint

Circumduction and rotation are carried out by a combination of these muscles