Kinesiology of the Wrist

Question 1

What is the significance of the wrist?

Answer 1

allows hands optimal positioning for prehension

often in static position stabilizing hand for distal movement

Question 2

what is the wrists position of fx?

Answer 2

10°-15° wrist extension
10° ulnar deviation
2nd metacarpal aligned with radius
aka “position of fixation”

Question 3

what are the bones of the wrist?

Answer 3

distal radius + ulna

scaphoid, lunate, triquetrium, pisiform, hamate, capitate, trapezium, trapezoid

Question 4

what makes up the proximal carpal row?

Answer 4

scaphoid
lunate
triquetrium
pisiform

Question 5

what is the significance of the scaphoid?

Answer 5

largest bone in wrist

most commonly fractured

Question 6

what is the significance of the lunate?

Answer 6

proximal to capitate
2nd most fractured in wrist
most dislocated b/c it moves alot

Question 7

what is the significance of the triquetrium?

Answer 7

distal to ulnar styloid
3rd most fractured bone in wrist
slides during deviation

Question 8

what is the significance of the pisiform?

Answer 8

only wrist bone with tendon (FCU)

lots of movement (flex, ext, radial + ulnar dev)

Question 9

what does the hook of hamate act as?

Answer 9

protection for ulnar nerve

Question 10

what is the significance of the trapezium?

Answer 10

very mobile (4 thumb)
lots of wear
critical link btwn carpals
close to FCR

Question 11

What are the ligaments of the wrist?

Answer 11

lateral collateral, central collateral, medial collateral

Question 12

what are the fxs of the ligaments of the wrist?

Answer 12

restrict motion
support motion
induce bony displacement
transmit precise tension loads (falling)

Question 13

what are the classifications of wrist ligaments?

Answer 13

extrinsic: radius and carpals, carpals and metacarpals
intrinsic: btwn carpals, originate & insert on carpals

Question 14

what is the dorsal ligament of the wrist? what do they do?

Answer 14

dorsal radio-carpal that checks flexion, shortens for extension

Question 15

what are the volar ligaments of the wrist? what do they do?

Answer 15

volar radio-carpal: strongest
volar ulnar-carpal: forms roof of carpal tun.

check extension, shortens for flexion

Question 16

what are the collateral ligaments of the wrist? what do they do?

Answer 16

radial collateral: check ulnar, shortens for radial

ulnar collateral: check radial, short for ulnar

Question 17

what is the significance of the intrinsic ligaments of the wrist?

Answer 17

btwn carpal bones
obliquity allows movement btwn carpal bones
anchor ligaments around capitate
protect wrist from impact

Question 18

Where do you find the triangular fibrocartilage complex (TFCC)?

Answer 18

occupies most of the space btwn distal ulna & carpal bones

Question 19

what is the fx of the TFCC?

Answer 19

stabilizer of the DRUJ

important during pronation and supination

Question 20

when does injury to TFCC usually occur?

Answer 20

rackets sports and slip and fall injuries that cause ulnar side wrist pain after distal radius fracture

Question 21

what is prayer position?

Answer 21

volar ligaments long, dorsal short

Question 22

what is inverted prayer position?

Answer 22

volar ligaments short, dorsal long

Question 23

what is the nerve/action of the flexor carpi ulnaris?

Answer 23

ulnar nerve

flexion & ulnar deviation

Question 24

what is the nerve/action of the flaxor carpi radialis?

Answer 24

median nerve

flexion & radial deviation

Question 25

what is the nerve/action of the palmaris longus?

Answer 25

median nerve | flexion of wrist

Question 26

what is the nerve/action of the extensor carpi radialis longus?

Answer 26

radial nerve | extension & radial deviation

Question 27

what is the nerve/action for the extensor carpi radialis brevis?

Answer 27

radial nerve | extension & weak radial deviation

Question 28

what should OT remember for muscles potential for movement?

Answer 28

any muscle that crosses any joint has the potential to move that joint

Question 29

what is circumduction of wrist?

Answer 29

combination of all wrist motions

Question 30

what movement is the radio-carpal joint responsible for?

Answer 30

first 2/3 of extension | second 1/2 of flexion

Question 31

what is the arthrokinematics of the radio-carpal joint?

Answer 31

concave distal radius convex carpal row (move together)

Question 32

what is the mid-carpal joint responsible for?

Answer 32

last 1/3 of extension | first 1/2 of flexion

Question 33

what is the arthrokinematics of the mid-carpal joint?

Answer 33

translational glides | move opposite

Question 34

what are the implications for wrist ligaments in cast positioning?

Answer 34

dorsal ligament: longer volar ligament: shorter will get ulnar dev 1st pronation but no supination b/c bones havent moved