Posterior Compartment Deep Forearm

Question 1

Supinator (origin)

Answer 1

posterolateral surface of ulna below radial notch; lateral epicondyle; radial collateral and annular ligaments

Question 2

Supinator (insertion)

Answer 2

Lateral and adjacent posterior and anterior aspects of proximal shaft of radius

Question 3

Supinator (action)

Answer 3

supination of forearm (and hand)

Question 4

Supinator (innervation)

Answer 4

Radial nerve

Question 5

abductor pollicis longus (origin)

Answer 5

posterior surface of ulna and radius; interosseous membrane

Question 6

abductor pollicis longus (insertion)

Answer 6

base of first metacarpal

Question 7

abductor pollicis longus (action)

Answer 7

abduction and extension of thumb; Radial deviation flexion of hand at wrist

Question 8

abductor pollicis longus (innervation)

Answer 8

Radial nerve

Question 9

extensor pollicis longus (origin)

Answer 9

posterior surface of middle 1/3 of ulna; interosseous membrane

Question 10

extensor pollicis longus (insertion)

Answer 10

distal phalanx of thumb

Question 11

extensor pollicis longus (action)

Answer 11

extension of proximal and distal phalanges of thumb; extension and adduction of metacarpal of thumb

Question 12

extensor pollicis longus (innervation)

Answer 12

radial nerve

Question 13

Extensor Pollicis Brevis (origin)

Answer 13

posterior surface of radius and interosseous membrane

Question 14

Extensor Pollicis Brevis (insertion)

Answer 14

proximal phalanx of thumb

Question 15

Extensor Pollicis Brevis (action)

Answer 15

extension of proximal phalanx and metacarpal of thumb, abduction of hand at wrsit

Question 16

Extensor Pollicis Brevis (innervation)

Answer 16

radial nerve

Question 17

extensor indicis (origin)

Answer 17

posterior surface of ulna; interosseous membrane

Question 18

extensor indicis (insertion)

Answer 18

extensor expansion of index finger

Question 19

extensor indicis (action)

Answer 19

extension and adduction of index finger

Question 20

extensor indicis (innervation)

Answer 20

radial