Posterior Forearm Muscles

Question 1

Brachioradialis

Answer 1

Proximal: lateral supracondylar ridge & intermuscular septum
Distal: lateral radial styloid process
Innervation: radial nerve (C5-C8)
Blood supply: recurrent radial artery
Functions: elbow FLX (in neutral position)

Question 2

Extensor Carpi Radialis Longus

Answer 2

Proximal: distal 1/3 of lateral supracondylar ridge
Distal: dorsal base of 2nd metacarpal
Innervation: radial nerve (C6-C7)
Blood supply: radial artery
Functions: wrist radial deviation & EXT

Question 3

Extensor Carpi Radialis Brevis

Answer 3

Proximal: common tendon of lateral epicondyle
Distal: dorsal base of the 3rd metacarpal
Innervation: radial nerve (C6-C7)
Blood supply: radial artery
Functions: wrist radial deviation & EXT

Question 4

Extensor Digitorum

Answer 4

Proximal: common tendon around lateral epicondyle
Distal: dorsal expansion of digits 2-5
Innervation: posterior interosseous nerve (C6-C8)
Blood supply: posterior interosseous artery
Functions: wrist EXT, radial deviation, & EXT digits 2-5

Question 5

Extensor Digiti Minimi

Answer 5

Proximal: common tendon around lateral humeral epicondyle
Distal: dorsal expansion on the 1st phalanx of 5th digit
Innervation: posterior interosseous nerve (C6-C8)
Blood supply: posterior interosseous artery
Functions: wrist EXT, ulnar deviation, & 5th digit EXT

Question 6

Extensor Carpi Ulnaris

Answer 6

Proximal: lateral humeral epicondyle & dorsal ulna
Distal: base of 5th metacarpal ulnar side
Innervation: posterior interosseous nerve (C6-C8)
Blood supply: ulnar artery
Functions: wrist EXT & ulnar deviation

Question 7

Supinator

Answer 7

Proximal: lateral humeral epicondyle, supinator crest, radial collateral ligament & annular ligament
Distal: dorsal & lateral surface of the radius
Innervation: posterior interosseous nerve (C6)
Blood supply: radial recurrent artery
Functions: forearm SUP

Question 8

Extensor Indicis

Answer 8

Proximal: dorsal distal ulna & interosseous membrane
Distal: posterior digital expansion of the index
Innervation: posterior interosseous nerve(C6-C7)
Blood supply: posterior interosseous artery
Functions: wrist & index finger EXT

Question 9

Abductor pollicis longus

Answer 9

Proximal: dorsal radius/ulna & interosseous membrane
Distal: radial side base of 1st metacarpal
Innervation: posterior interosseous nerve (C6-C7)
Blood supply: posterior interosseous artery
Functions: radial deviation of the wrist & ABD of the thumb

Question 10

Extensor Pollicis Longus

Answer 10

Proximal: dorsal distal 1/3 of ulna & interosseous membrane
Distal: base of the distal phalanx of the thumb
Innervation: posterior interosseous nerve (C6-C7)
Blood supply: posterior interosseous artery
Functions: wrist radial deviation & thumb EXT

Question 11

Extensor Pollicis Brevis

Answer 11

Proximal: dorsal radius & lateral interosseous membrane
Distal: base of the 1st phalanx of the thumb
Innervation: posterior interosseous nerve (C6-C7)
Blood supply: posterior interosseous artery
Functions: wrist radial deviation & thumb EXT/ABD