Posterior compartment- deep muscles

Question 1

Insertion of supinator?

Answer 1

Radius (between radial tuberosity and insertion of pronator teres)

Question 2

Innervation of supinator?

Answer 2

Radial n.

C6, C7

Question 3

Action of supinator?

Answer 3

Radioulnar joints: supination

Question 4

Origin of abductor pollicis longus?

Answer 4

Radius and ulna (dorsal surfaces, interosseous membrane)

Question 5

Insertion of abductor pollicis?

Answer 5

Base of 1st metacarpal

Question 6

Innervation of abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis? (all deep muscles except supinator)

Answer 6

Radial n.

C7, C8

Question 7

Action of abductor pollicis longus?

Answer 7

Radiocarpal joint: abduction of the hand

Carpometacarpal joint of thumb: abduction

Question 8

Origin of extensor pollicis brevis?

Answer 8

Radius (posteiror surface) and interosseous membrane

Question 9

Insertion of extensor pollicis brevis?

Answer 9

Base of the proximal phalanx of thumb

Question 10

Action of extensor pollicis brevis?

Answer 10

Radiocarpal joint: radial deviation

Carpometacarpal and MCP of thumb: extension

Question 11

Origin of extensor pollicis longus?

Answer 11

Ulna (posterior surface) and interosseous membrane

Question 12

Insertion of extensor popllicis longus?

Answer 12

Base of distal phalanx of thumb

Question 13

Action of extensor pollicis longus?

Answer 13

Wrist: extension and radial deviation of hand
Carpometacarpal of thumb: adduction
MCP and IP of thumb: extension

Question 14

Origin of extensor indicis?

Answer 14

Ulna (posterior surface) and interosseous membrane

Question 15

Insertion of extensor indicis?

Answer 15

Posterior digital extension of 2nd digit

Question 16

Action of extensor indicis?

Answer 16

Wrist: extension

MCP, PIP, and DIP of 2nd digit: extension

Question 17

Origin of supinator? (4)

Answer 17

Olecranon, lateral epicondyle of humerus, radial collateral ligament, annular ligament of radius