Posterior forearm

Question 1

Muscles of posterior forearm rule

Answer 1

3 to wrist
3 to fingers
3 to thumb

Question 2

What are all these muscles supplied by?

Answer 2

Radial nerve (superficial and deep/posterior interosseus branch)

Question 3

2 muscles not to forget about

Answer 3

Aconeus (elbow stability)

Brachioradialis (on border of anterior and posterior, thumb side)

Question 4

3 wrist muscles

Answer 4

Extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris

Question 5

3 finger muscles

Answer 5

extensor digitorum communis
extensor digit minimi
extensor indicis

Question 6

3 thumb muscles

Answer 6

extensor pollucis longus
extensor pollucis brevis
abductor pollucis longus

Question 7

Function posterior forearm

Answer 7

extensors

Question 8

What do the thumb muscles create?

Answer 8

Anatomical snuff box

Question 9

Origin for all posterior forearm

Answer 9

Lateral epicondyle (common extensor origin)

Question 10

Brachioradialis O and I

Answer 10

O: lateral supracondylar ridge
I: Distal radius

Question 11

brachioradialis A and I

Answer 11

A: flexes at elbow when mid prone (beer drinking)
I: Radial nerve

Question 12

Extensor carpi radialis (longus and brevis)

Answer 12

O: supracondylar ridge humerus

I: longus: dorsal base of 2nd metacarpal
brevis: same but third metacarpal base

A: extends and abduct at the wrist

Question 13

Extensor digitorum communis

Answer 13

O: lateral epi
I: extensor expansions
A: extends fingers at interphalangeal and metacarpophalangeal joints

Question 14

How 4 tendons linked of EDC?

Answer 14

Juncturae tendinum (fibrous bands) prevents extension of middle/ring finger if other fingers are flexed

Question 15

Extensor digiti minimi

Answer 15

I: extensor hood of little finger
A: extends little finger and wrist

Question 16

Extensor carpi ulnaris

Answer 16

O: humeral head: lateral epi
ulnar head: olecranon
I: base of 5th metacarpal
A: adduction and extension of wrist

Question 17

Deep muscles posterior arm

Answer 17

Supinator
Abductor pollucis longus
Extensor pollucis longus and brevis
Extensor indicis

Question 18

Superficial posterior arm muscles

Answer 18

Brachioradialis
Extensor carpi radialis (longus and brevis)
Extensor carpi ulnaris 
Extensor digitorum
Extensor digiti minimi
Aconeus

Question 19

Abductor pollucis longis O and I

Answer 19

O: interosseus membrane of radius and ulna
I: base of 1st metacarpal

Question 20

abductor pollucis longus A and I

Answer 20

A: Abducts the thumb and extension at carpometacarpal joint
I: radial nerve (posterior interosseus)

Question 21

Extensor pollucis longus O and I

Answer 21

O: posterior ulna and interosseus membrane
I: Distal phalanx of thumb
A: extends thumb at all joints
I: radial nerve

Question 22

extensor pollucis brevis

Answer 22

O: posterior radius and interosseus membrane
I: proximal phalanx
A: extends thumb (NOT AT interphalangeal joints)
I: radial nerve (posterior interosseus)

Question 23

Extensor indicis

Answer 23

O: posterior ulna and interosseus membrane
I: extensor hood index finger
A: extends index finger independently from others
I: radial nerve (posterior interosseus)

Question 24

Branches radial nerve

Answer 24

Long and lateral triceps brachii
posterior cutaneous arm
Lower lateral cutaneous nerve of arm
posterior cutaneous nerve of forearm

Question 25

Final branches radial nerve

Answer 25

Deep motor branch

Superficial sensory branch - dorsal lateral 3 digits

Question 26

When does radial nerve change name and what to?

Answer 26

Through supinator to posterior compartment = posterior interosseus nerve

Question 27

Whats anatomical snuff box?

Answer 27

Created by thumb muscles

Ulna border - extensor pollucis longus

radial border - abductor pollucis longus and extensor pollucis brevis

floor - scaphoid and trapezium

Question 28

Snuff box isss?

Answer 28

Has radial artery and cephalic vein inside
Radial nerve over top
Scaphoid bone fracture can be palpated here (easy to miss on x-ray)