Arm/Forearm/Hand Anatomy

Question 1

what comprises the humeroradial joint?

Answer 1

head of radius, annular ligament, and capitulum of humerus

Question 2

where does the radius attach?

Answer 2

at humerus capitulum with annular ligament

and from that ligament to the radial notch of ulna

Question 3

does to annular ligament move?

Answer 3

no, radius moves inside of it

Question 4

humero-ulnar joint

Answer 4

trochlear notch/olecranon of ulna and trochlea of humerus

Question 5

what muscles extend the forearm

Answer 5

triceps brachii and anconeus

plus soome forearm extensors

Question 6

what muscles flex elbow

Answer 6

biceps and brachialis, helped by bracioradialis

Question 7

where do forearm extensors and flexors originate ?

Answer 7

extensors from lateral epicondyle of the humerus

flexors from medial epicondyle of humerus

Question 8

major upper arm supinator?

Answer 8

biceps brachii

Question 9

carpals articulate with radius or ulna

Answer 9

radius

Question 10

carpals rows % involvement with flexion and extension

Answer 10

flexion - 60% distal row

Extension - 60% proximal row

Question 11

“cant do push up”…why?

Answer 11

ganglion cyst in scaphoid-lunate ligament –> pinches bone in extension

Question 12

how should you cast a metacarpal-phalange joint?

Answer 12

flexion is position of safety….NOT extension!!

Question 13

metacarpal collateral ligaments

Answer 13

loose in extension and tight in flexion

Question 14

PIP proximal interphalange

Answer 14

collateral ligaments tight in all phases f flexion and extention due to origin in the center of the arc of rotation

Question 15

monteggia fracture

Answer 15

olecranon fracture of ulna at radial attachement

Question 16

carpal lunate dislocation

Answer 16

“burning”, affects median nerve
Cs (capitate lunate radius) out of algnment
look from lateral xray!!

Question 17

Kienbocks aseptic necrosis of the lunate

Answer 17

loss of blood supply to lunate
secondary dislocation, stress, cortisone-induced
often spontaneous

Question 18

both 4th and 5 metacarpals articulate with..

Answer 18

hamate carpal

Question 19

best view for a 4th/5th MC-hamate fracture

Answer 19

xray 15 degrees pronation and 5 degrees lateral

Question 20

can only bend PIPs not DIPs

Answer 20

flexor digitorum profundus rupture

Question 21

game keepers thumb

Answer 21

avulsion of ulnar collateral ligament at MP junction of the thumb
cant pinch against thumb since there is no stability

Question 22

wing scapula

Answer 22

long thoracic nerve issue

serratus anterior deficit and scapula comes away from wall

Question 23

pec major deficit

Answer 23

usually from large force
can tear off of humerus
findings: echymoises bruising, depression in lateral chest

Question 24

where to inject around acromion?

Answer 24

dont inject below two fingers of acromion edge so that you dont inject the axillary artery

Question 25

what innervates trapezius?

Answer 25

accessory nerve cnxi

Question 26

what does first 15% of arm abduction?

Answer 26

supraspinatous

Question 27

what three nerves make repairing a distal biceps rupture diffilcut?

Answer 27

posterior interosseus branch of radial nerve, superficial sensory branch of radial nerve, and lateral antebrachial cutaneous nerve

Question 28

effects due to laceration of ulnar nerve?

Answer 28

a laceration at any level will disrupt the coordination of hand muscles and movement
clumsy (no longer can play musical instrument)

Question 29

what nerve coordinates many fast motor movements of hand?

Answer 29

ulnar

Question 30

effects of median nerve laceration?

Answer 30

numbness of the hand since most of the palm and radial 3.5 digits are numb
innability to elevate thumb away from palm plane (opposition)

Question 31

lateral epicondylitis

Answer 31

inflammation of the periosteum of the lateral epicondyle of the humerus

Question 32

elbow tendinitis

Answer 32

tennis elbow
repeated use of superficial extensor muscles of forearm–> strain on common lateral extensor tendon producing lateral epicondylitis

Question 33

mallet/baseball finger

Answer 33

DIP is flexed down like a mallet;

from suddenly being forced into extreme flexion tearing the attachment of the tendon to the distal phalanx

Question 34

olecranon fracture

Answer 34

fall on elbow + sudden powerful triceps contraction –>fractured olecranon is pulled away by triceps tendon

Question 35

pronator syndrome

Answer 35

nerve entrapment – the compression of median nerve near elbow
symptoms: proximal anteriorforearm pain and hypesthesia (decreased sensation) in palmars aspects of the radial 3.5 digits

Question 36

anterior interosseus syndrome

Answer 36

when attempting to make ok sign, a pinch posture results due to abcense of flexion in IP joint of thumb and DIP of 2nd finger

Question 37

effects of median nerve laceration

Answer 37

-no flexion of 1-3 PIPs (4th/5th weakened)