Posterior Compartment of the Forearm

Question 1

brachioradialis

Answer 1

O: lateral supracondylar ridge of humerus
I: styloid process of ulna
A: elbow flexio/prnation when forearm is supinated/supination when forearm is pronated
I: radial

Question 2

extensor carpi ulnaris

Answer 2

O: lateral epicondyle of humerus via common extensor tendon/posterior lateral border of ulna
I: base of 5th metacarpal, medial side
A: wrist extension/ulnar deviation

Question 3

extensor digitorum

Answer 3

O: lateral epicondyle of humerus via common extensor tendon
I: extensor expansion of digits 2-5
A: MCP extension of digits 2-5/wrist extension
I: radial

Question 4

extensor digiti minimi

Answer 4

O: lateral epicondyle of humerus via common extensor tendon
I: proximal phalanx of 5th digit, dorsal surface/4th tendon of extensor digitorum
A: extension of 5th digit/abudction of 5th digit
I: radial

Question 5

extensor indicis

Answer 5

O: posterior surface of ulna/interosseous membrane
I: bases of middle and distal phalanges of 2nd digit (via tendon of extensor digitorum)
A: extension of 2nd digit/wrist extension
I: radial

Question 6

supinator

Answer 6

O: lateral epicondyle of humerus/supinator crest
I: proximal anterolateral surface of radius
A: supination
I; radial

Question 7

extensor carpi radialis longus

Answer 7

O: lateral supracondylar ridge of humerus
I: base of 2nd metacarpal, dorsal surface
A: wrist extension/radial deviation

Question 8

extensor carpi radialis brevis

Answer 8

O: lateral epicondyle of humerus via common extensor tendon
I: base of 3rd metacarpal, dorsal surface
A: wrist extension, radial deviation
I: radial

Question 9

abductor pollicis longus

Answer 9

O: posterior surface of ulna and radius/interosseous membrane
I: base of 1st metacarpal, lateral surface
A: abduction of 1st metacarpal, radial deviation
I:radial

Question 10

extensor pollicis brevis

Answer 10

posterior surface of radius/interosseous membrane
I: base of proximal phalanx of pollex, posterior surface
A: extension of pollex/radial deviation
I: radial

Question 11

extensor pollicis longus

Answer 11

O: middle posterior lateral surface of ulna/interosseous membrane
I: base of distal phalanx of pollex, dorsal surface
A: extension of pollex/wrist extension/radial deviation