Untitled Quiz

The distal quarter of the anterior surface of the ulna.

The distal quarter of the anterior surface of the radius.

Abducts the thumb and extends it at the carpometacarpal joint.

Extends the distal phalanx of the thumb at the interphalangeal joint and other relevant joints.

Extends the proximal phalanx of the thumb at the metacarpophalangeal joint.

Relatively weak flexion of the forearm, most effective with the forearm in a mid-pronated position.

Extends and abducts the hand at the wrist, involved in fist clenching.

Lateral supraepicondylar ridge of the humerus (proximal two thirds).

The Medial epicondyle of the humerus (common flexor origin).

Flexes and abducts the hand (at the wrist).

Ulnar nerve (C7, C8).

Shafts of middle phalanges of medial four digits.

Ulnar nerve (C8, T1).

Flexes distal phalanges 4 and 5.

Anterior surface of radius and interosseous membrane.

Flexes the distal phalanx of the thumb.

It attaches to the posterior surface of the distal third of the ulna and the interosseous membrane proximally and to the extensor expansion of the 2nd digit distally.

The Extensor Indicis is innervated by the Posterior interosseous nerve, which is a branch of the Deep branch of the Radial Nerve (C7, C8).

It helps with supinating the forearm, rotating the radius to turn the palm anteriorly or superiorly, especially when the elbow is flexed.

The Opponens Pollicis muscle attaches to the Tubercles of Scaphoid and Trapezium proximally and to the lateral side of the 1st metacarpal distally.

The Opponens Pollicis muscle is innervated by the Recurrent branch of the Median nerve (C8, T1).

It helps to oppose the thumb by drawing the 1st metacarpal medially to the center of the palm and rotating it medially.

The Abductor Pollicis Brevis muscle helps to abduct the thumb and oppose it by pulling it away from the index finger.

The Flexor Pollicis Brevis muscle helps to flex the thumb by bending it towards the palm.