Posterior Forearm

Question 1

superficial group of posterior forearm compartment (6)

Answer 1

brachioradialis 
extensor carpi radialis longus 
extensor carpi radialis brevis
extensor digitorum longus 
extensor digiti minimi 
extensor carpi ulnaris

Question 2

deep group of posterior forearm compartment

Answer 2

supinator
abductor pollicis longus
extensor pollicis longus
extensor indicies

Question 3

the superficial group and deep group of extensor muscles are separated by

Answer 3

the radial nerve

Question 4

all muscles of the posterior forearm are innervated by the ______ nerve by either the _____ branch or _______ -______ nerve branch

Answer 4

radial nerve by the
deep branch or
posterior interosseous nerve branch

Question 5

origin of brachioradialis m

Answer 5

supra-epicondylar ridge of humerus

Question 6

insertion of brachioradilis m

Answer 6

lateral distal radius proximal styloid process

Question 7

innervation of brachioradialis m

Answer 7

superficial branch of radial n

Question 8

action of brachioradialis m

Answer 8

weak arm flexion

maximal when mid-pronated

Question 9

brahcioradialis
extensor carpi radialis longus
extensor carpi radialis brevis
are all in what group of extensor muscles

Answer 9

the radialis group is all superficial

Question 10

extensor carpi ulnaris
extensor digitorum
extensor digiti minimi
along with the radialis group make up the

Answer 10

superficial layer

Question 11

supinator
extensor pollicis longus 
abductor pollicis longus
extensor pollicis brevis 
extensor indicis 
are all in what layer of the posterior forearm

Answer 11

all are in the deep layer

Question 12

superficial lateral group of posterior forearm consists of

Answer 12

extensor carpi radialis longus

extensor carpi radialis brevis

Question 13

origin/insertion of extensor carpi radialis longus

Answer 13

lateral supraepicondylar ridge of humerus to dorsal side of 2nd metacarpal

Question 14

action of extensor radialis longus

Answer 14

extend/abduct hand at wrist

Question 15

innervation of extensor radialis longus

Answer 15

radial n

Question 16

origin/insertion of extensor carpi radialis brevis

Answer 16

lateral epicondyle of humerus to dorsal base of 3rd metacarpal

Question 17

action of extensor carpi radialis brevis

Answer 17

extend/abduct hand at wrist

Question 18

origin/insertion of extensor carpi ulnaris

Answer 18

lateral epicondyle;posterior ulna via shared aponeurosis to dorsal base of 5th metatarsal

Question 19

extensor carpi ulnaris innervation

Answer 19

posterior interosseous nerve

branch of deep branch of the radial nerve

Question 20

extensor carpi ulnaris action

Answer 20

extend and adducts hand at wrist

Question 21

origin/insertion of extensor digitorum

Answer 21

lateral epicondyle to extensor expansion of medial 4 digits

Question 22

action of extensor digitorum

Answer 22

extends primarily at MPJ but also IPJ

Question 23

innervation of extensor digitorum m

Answer 23

posterior interosseous n

Question 24

origin/insertion of extensor digiti minimi

Answer 24

lateral epicondyle to extensor expansion of 5th digit

Question 25

action of extensor digiti minimi

Answer 25

extends 5th digit at MPJ but also IPJ

Question 26

innervation of extensor digiti minimi

Answer 26

posterior interosseous n

Question 27

``` Supinator extensor indices abductor pollicis longus extensor pollicis longus extensor pollicis brevis are part of the ```

Answer 27

deep group of extensor muscles

Question 28

origin/insertion supinator

Answer 28

deep part - ulna | superficial part - lateral condyle to radial tubercle; oblique line of radius

Question 29

action of supinator

Answer 29

supinates forearm

Question 30

innervation of supinator

Answer 30

deep branch of radial n

Question 31

origin/insertion of extensor indices

Answer 31

posterior surface distal ulna and IO membrane to extensor expansion of 2nd digit

Question 32

action of extensor indices

Answer 32

extend 2nd digit; assists extending hand at wrist

Question 33

innervation of extensor indices

Answer 33

posterior interosseous n

Question 34

origin/insertion of abductor pollicis longus

Answer 34

posterior half of ulna, radius IO to base of 1st metacarpal

Question 35

action of abductor pollicis longus

Answer 35

abduct thumb and extends at carpometacarpal joint

Question 36

innervation of abductor pollicis longus

Answer 36

posterior interosseous n

Question 37

origin/insertion extensor pollicis longus

Answer 37

posterior middle third ulna and IO to dorsal base of distal phalanx of thumb

Question 38

action of extensor pollicis longus

Answer 38

extend distal phalanx of thumb at PIJ; extends at MPJ and carpometacarpal joints

Question 39

innervation of extensor pollicis longus m

Answer 39

posterior interosseous n

Question 40

origin/insertion of extensor pollicis brevis

Answer 40

posterior distal radius and IO membrane to dorsal base of proximal phalanx of thumb

Question 41

action of extensor pollicis brevis

Answer 41

extend proximal phalanx of thumb at MPJ; extends carpometacarpal joints

Question 42

innervation of extensor pollicis brevis

Answer 42

posterior interosseous n

Question 43

extensor digitorum pulls on what structure causing the IP joint to extend

Answer 43

extensor expansion (a tendenous structure that extends from the proximal phalanx to the distal phalanx) connected to the extensor hood

Question 44

lumbricals are able to extend the IP joints by their insertion in what structure

Answer 44

the extensor hood

Question 45

describe the extensor expansion

Answer 45

tendonous structure that extends across the dorsal aspect of the phalanges that allows for extension of phalanges (even during flexion of MCP joint)

Question 46

the common interosseous artery gives rise to what two arteries of the forearm

Answer 46

the anterior interosseous a (the perforating branch of the anterior interosseous) posterior interosseous a

Question 47

what a supply the posterior forearm and hand

Answer 47

``` common interosseous and its branches (A and P) perforating branch of anterior interosseous radial a (deep palmar, dorsal palmar arches) ```

Question 48

innervation to the posterior forearm is performed by what n

Answer 48

radial n and its branches (superficial branch) (deep branch --> posterior interosseous n)

Question 49

the deep branch of the radial n becomes the posterior interosseous after it crosses what muscle

Answer 49

becomes posterior interosseous as it begins passing through supinator

Question 50

radial n injuries subsequent to a proximal humerus injury may result in what lack of function

Answer 50

no elbow extension; weak supination

Question 51

radial n injuries subsequent to a a mid-humerus injury may result in what lack of function (in the radial groove)

Answer 51

muscle weakness depends on locaiton

Question 52

distal humerus injuries, such as repetitive forearm rotation, tennis elbow, compression, may result in what symptoms

Answer 52

wrist drop: inability to extend the hand, MCP joint and fully extend forearm

Question 53

trauma to the raidal n in the wrist may result in what symptoms

Answer 53

no sensory innervation to dorsal hand

Question 54

causes and symptoms of wrist drop

Answer 54

radial n injury in the distal humerus paralysis of extensors of wrist and fingers results in inability to extend flexors overrepresented

Question 55

lateral epicondylitis symptoms and primary muscles involved

Answer 55

overuse injury of extensors from lateral epicondyle swelling, tenderness, pain in wrist extension Ext. Carpi radialis brevis ext. digitorum

Question 56

testing the radial n involves

Answer 56

testing resistance to extension by extensor digitorum | radial n only nerve to extend MCP joint

Question 57

contents of the anatomical snuffbox

Answer 57

superficial radial n | radial a

Question 58

borders of anatomical snuffbox

Answer 58

``` Extensor pollicis brevis extensor pollicis longus abductor pollicis longus floor - scaphoid bone roof - superficial radial nerve branches ```

Question 59

DeQuervain's disease

Answer 59

tenosynovitis of first compartment of thumb to Abductor pollicis longus, extensor pollicis brevis + Finkelsteins test