Posterior Forearm

Question 0

Extensor carpi radialis longus

Answer 0

O: lateral supraepicondylar ridge of humerus
I: dorsal base of 2nd metacarpal
N: radial nerve (C6,7)
A: radial, radial recurrent, radial collateral aa
F: extend and abduct wrist

Question 1

Brachioradialis

Answer 1

O: proximal supraepicondylar ridge of humerus
I: distal lateral surface of radius (prox to styloid)
N: radial nerve (C5,6,7)
A: radial a, radial & ulnar recurrent aa
F: flex forearm & supination when fully pronated

Question 2

Extensor carpi radialis brevis

Answer 2

O: lateral epicondyle of humerus
I: dorsal base of 3rd metacarpal
N: deep branch of radial n (C7,8)
A: radial, radial recurrent, radial collateral aa
F: wrist extension and abduction

Question 3

Extensor digitorum

Answer 3

O: lateral epicondyle of humerus
I: extensor expansions of medial four digits
N: deep branch of radial n (C7,8)
A: radial & posterior interosseous aa
F: extends medial four digits (1- at MCP 2- at DIP/PIP)

Question 4

Extensor digiti minimi

Answer 4

O: lateral epicondyle of humerus
I: extensor expansion of 5th digit
N: deep branch of radial n (C7,8)
A: posterior interosseous, radial recurrent, radial collateral aa
F: extends 5th digit (1- at MCP, 2- at DIP/PIP)

Question 5

Extensor carpi ulnaris

Answer 5

O: lateral epicondyle of humerus/posterior border of ulna
I: dorsal base of 5th metacarpal
N: deep branch of radial n (C7,8)
A: ulnar, radial recurrent, radial collateral aa
F: extension and adduction of wrist

Question 6

Anconeous

Answer 6

O: lateral epicondyle
I: lateral olecranon & posterior ulna
N: radial nerve (C7,8, T1)
A: middle collateral & recurrent interosseous aa
F: forearm extension & abduction of ulna during pronation

Question 7

Supinator

Answer 7

O: upper head- lateral epicondyle, radial collateral lig, annular lig. Deep head- supinator fossa & ulnar crest
I: lateral, anterior, & posterior surface of prox radius
N: deep branch of radial n (C7,8)
A: posterior interosseous, radial, radial recurrent aa
F: supination

Question 8

Abductor pollicis longus

Answer 8

O: proximal posterior surface of ulna, radius, & interosseous membrane
I: base of 1st metacarpal
N: posterior interosseous n (C7,8)
A: posterior interosseous a
F: abduction and extension of thumb

Question 9

Extensor pollicis longus

Answer 9

O: posterior middle surface of ulna/interosseous membrane
I: dorsal base of distal phalanx of thumb
N: posterior interosseous n (C7,8)
A: posterior interosseous a
F: extends distal phalanx of thumb (MCP & CMC)

Question 10

Extensor pollicis brevis

Answer 10

O: posterior distal third of radius/interosseous membrane
I: dorsal base of proximal phalanx of thumb
N: posterior interosseous n (C7,8)
A: posterior interosseous a
F: extends proximal phalanx of thumb (MCP/CMC)

Question 11

Extensor indicis

Answer 11

O: posterior distal third of ulna/interosseous membrane
I: extensor expansion of 2nd digit
N: posterior interosseous n (C7,8)
A: posterior interosseous a
F: extends 2nd digit/helps extend wrist