muscles of the wrist

Question 1

primary roles of the muscles of the wrist

Answer 1

provide a stable base for the hand

adjust its position for optimal length-tension in the long finger muscles

work in synergy

Question 2

flexor muscles

Answer 2

common origin from the medial epicondyle

all pass under the flexor retinaculum except the palmaris longus

Question 3

prime wrist flexors

Answer 3

flexor carpi radialis

flexor carpi ulnaris

palmaris longus

Question 4

flexor carpi radialis

Answer 4

will flex and radially deviate the wrist when working on its own

Question 5

flexor carpi ulnaris

Answer 5

will flex and ulnarlly deviate the wrist

passes over the pisiform bone

functions as an anatomic pulley –> gets deflected for the joint axis–> increases the movement arm and produces torque

Question 6

palmaris longus

Answer 6

flexor, but will tense the palmar fascia

assist elbow flexion and pronation

absent in 10% of the population

Question 7

secondary movers

Answer 7

muscles recruited in time of need to move a larger load

flexor digitorum superficialis (FDS)

flexor digitorum profundus (FDP)

flexor pollicis longus (FPL)

primary responsibility is finger flexion

Question 8

what are the secondary movers dependent on

Answer 8

as multi-joint muscles, their ability to produce force at the wrist is dependent on a synergetic stabilizer to prevent full excursion at more distal joints

need to be stabilized in extension to protect against becoming actively insufficient

Question 9

extensor muscles

Answer 9

common origin from lateral epicondyle

Question 10

primary wrist extensors

Answer 10

extensor carpi ulnaris

extensor carpi radialis brevis

extensor carpi radialis longus

Question 11

extensor carpi ulnaris

Answer 11

will extend and ulnarlly deviate the wrist

acts as a stabilizer –> especially when were in wrist flexion –> important b/c wrist flexion tends to be an unstable position

Question 12

extensor carpi radialis brevis

Answer 12

has a central location on the wrist d/t insertion on third metacarpal

pure wrist extensor d/t location

Question 13

extensor carpi radialis longus

Answer 13

will extend and radially deviate the wrist –> d/t location of insertion on the second metacarpal

shows increased activity when either radial deviation or support against ulnar deviation is required

also active when forceful finger flexion motions are performed

BEST STABALZIER OF THE WRIST –> neutralizing synergy

Question 14

secondary wrist extensors

Answer 14

extensor digitorum

extensor indicis

extensor digiti minimi

extensor pollicis longus

extensor pollicis brevis

abductor pollicis longus

all have the potential to produce wrist extenstion

Question 15

where do EDM and EI insert

Answer 15

into the tendons of ED –> share a common function

ED will be more active

can also function as a wrist extensor

Question 16

extrinsic musculature of the thumb

Answer 16

cross wrist and has potential to add to movement

but shows little activity

Question 17

radial deviation

Answer 17

primarily a conjoint synergy b/w flexor carpi radialis and extensor carpi radialis longus

assisted by abductor pollicis longus and extensor pollicis brevis

Question 18

ulnar deviation

Answer 18

primarily a conjoint synergy of flexor capri ulnaris and extensor carpi ulnaris

Question 19

synergies at the wrist

Answer 19

conjoint synergy

neutralizing synergy

Question 20

conjoint synergy

Answer 20

motions of flexion, extension, RD and UD

Question 21

neutralizing synergy

Answer 21

during finger movements (flexion or extension)

you need activity of wrist musculature to prevent unwanted wrist movements

avoid active insufficiency

ex: finger flexion by FDS and FDP would result in wrist flexion unless there is contraction of wrist extensors

Question 22

functional position of the wrist and hand

Answer 22

grasp is the most important position of the hand

position from which optimal function is most likely to occur

not necessarily the position of immobilization as this is depending on the disability

Question 23

function position of the wrist and hand ( wrist measurements)

Answer 23

20 degrees of extension

10 degrees of ulnar deviation

putting the finger flexors at optimal length

Question 24

functional position of the hand and wrist (finger measurements)

Answer 24

45 degrees of MP flexion

30 degrees of PIP flexion

slight flexion of DIP joints

Question 25

wrist extensors are _____ joint muscles

Answer 25

two or three

susceptible to becoming actively and passively insufficient

Question 26

extensors are actively insufficient when (too long)

Answer 26

too long –> can’t extend the wrist

elbow extension

wrist flexion

finger flexion

Question 27

extensors are actively insufficient when (too short)

Answer 27

can’t flex the wrist

wrist extension

elbow flexion

finger extension

Question 28

extensors are passively insufficient

Answer 28

elbow extension

wrist flexion

finger flexion

can ulnar/radial deviate to stretch a specific side