Motor Control Exam 2

Question 1

When does the heel rocker take place in the gait cycle?

Answer 1

from initial contact to loading response

Question 2

When does the ankle rocker take place?

Answer 2

from time of flat foot to heel rise

Question 3

When does forefoot rocker take place?

Answer 3

lasts from heel rise until terminal stance (end of stance)

Question 4

What is probe reaction time?

Answer 4

the time it takes for the individual to start their response to the signal

Question 5

What does it mean if reaction time is slow?

Answer 5

the task is more difficult or complex for them

Question 6

What do the cell phone studies test?

Answer 6

structural interference vs. capacity interference

Question 7

What is structural interference?

Answer 7

physically interfering with what you are doing

Question 8

How is gait variability affected when executive function declines?

Answer 8

gait variability increases

Question 9

What happens to the timing of steps as cognitive functions decline?

Answer 9

timing of steps increases

Question 10

When does the stepping reflex disappear and reappear according to Thelen?

Answer 10

disappears at about 2-3 months and reappears at about 10-12 months

Question 11

Why are kids not able to walk until 10 to 18 months?

Answer 11

postural control

Question 12

What does gait look like for toddlers?

Answer 12

a lot movement from left to right for balance, large BOS, and small step length

Question 13

What are the 3 types of equilibriums for postural control?

Answer 13

Stable, unstable, and neutral

Question 14

What is meant by a stable equilibrium?

Answer 14

a small displacement leads to an unbalanced force that tends to restore the object to the equilibrium location

Question 15

What is meant by an unstable equilibrium?

Answer 15

a small displacement leads to an unbalanced force that further increases the displacement from the equilibrium?

Question 16

What is meant by a neutral equilibrium?

Answer 16

an equilibrium at any location

Question 17

What are the 4 components of balance?

Answer 17

center of mass, center of gravity, base of support, and center of pressure

Question 18

What is center of pressure?

Answer 18

where the resultant forces are under you foot or wherever you are pushing off (ground reaction force)

Question 19

When are COP and COM in the same location?

Answer 19

standing

Question 20

Where should COP be during gait?

Answer 20

want COP on the foot that is going to swing before it swings

Question 21

Why do you sway less when using your phone while standing?

Answer 21

less focused on swaying and more focused on using your phone

Question 22

True or false: People usually do better when told to focus on their body rather than the task.

Answer 22

False

Question 23

What are the 3 sensory systems in postural control?

Answer 23

visual, vestibular, somatosensory

Question 24

Which of the 3 sensory systems for postural control is the least important?

Answer 24

vestibular

Question 25

What is the vestibular system not good at detecting?

Answer 25

gravity

Question 26

What is the clinical test for sensory integration imbalance (CTSIB)?

Answer 26

taking sensory systems away to look at balance

Question 27

In the CTSIB, when did balance decrease?

Answer 27

when vision was taken away

Question 28

In the CTSIB, why did older people sway more when vision was taken away?

Answer 28

they are more reliant on vision

Question 29

Why do you sway more on a block of foam, even with eyes open?

Answer 29

the surface is less stable and the motor system is compromised

Question 30

When standing on a foam block, do you sway more with eyes open or closed?

Answer 30

eyes closed

Question 31

Does the block of foam change the somatosensory system?

Answer 31

no

Question 32

What are the components of the ankle strategy? (8 of them)

Answer 32

= used when perturbation is slow or has low amplitude - contact surface is firm, wide, and longer than foot - muscles recruited distal-to-proximal - head movements in-phase with hips - needs firm support surface - could be argued to be a reflexive movement - surface has to be longer than their foot

Question 33

What are the components of the hip strategy? (4 of them)

Answer 33

- used when perturbation is fast or has large amplitude - surface is unstable or shorter than feet - muscles recruited proximal-to-distal - head movement out-of-phase with hips

Question 34

What are the components of the stepping strategy? (3 of them)

Answer 34

- used to prevent a fall - used when perturbations are fast or large amplitudes - used when other strategies fail - body moves to "catch up with" base of support

Question 35

What are the 3 controls theories?

Answer 35

motor programs, muscles synergies, and feedback control

Question 36

What are the clinical implications for using the 3 control theories?

Answer 36

training the whole system (don't use only one theory within your rehab, rather combine the 3 theories)

Question 37

In the vestibular system, how many degrees of freedom are there for acceleration?

Answer 37

6

Question 38

How can you stimulate somatosensory perturbation?

Answer 38

move the floor underneath you

Question 39

Can you respond faster to somatosensory information or visual information?

Answer 39

somatosensory

Question 40

Do we end up using somatosensory or visual information more often?

Answer 40

visual

Question 41

Why are older adults more reliant on vision?

Answer 41

vestibular and somatosensory systems are not good enough (not developed or declined)

Question 42

Why does placing one finger on a stable surface improve your balance when standing tandem with your eyes closed?

Answer 42

provides proprioceptive input

Question 43

True or false: putting your body weight through the finger that is on the stable surface will improve your balance.

Answer 43

false

Question 44

Why is muscle emg more active when you are not touching the stable surface?

Answer 44

you are not able to make corrections earlier

Question 45

True or false: canes provide proprioceptive input.

Answer 45

true

Question 46

When is reaction time the fastest, during sitting or standing?

Answer 46

sitting, because it takes less effort to sit rather than to stand

Question 47

When is reaction time the fastest, when standing one 2 feet or 1 foot?

Answer 47

2 feet

Question 48

What is open-loop phase of an aim or reach?

Answer 48

movement you make without any feedback involved

Question 49

What is closed-loop phase during aim or reach?

Answer 49

movement you make with feedback involved

Question 50

What pathway controls the closed-loop phase?

Answer 50

corticospinal pathways

Question 51

What pathways control the open-loop phase?

Answer 51

extra pyramidal pathways

Question 53

True or false: the closed-loop is present during a movement with the eyes closed.

Answer 53

false

Question 54

Is closed-loop or open-loop more difficult to get back?

Answer 54

closed loop

Question 55

Is the wine glass effect a cerebrum issue?

Answer 55

no, it is a cerebellar and spinal cord issue

Question 56

If there is a stroke in the right hemisphere, what hand will power grip be lost on?

Answer 56

left hand

Question 57

What does Hick's law deal with?

Answer 57

reaction time

Question 57

If there is a stroke in the right hemisphere, the pincer grip is lost in what hand?

Answer 57

both the left and right hand

Question 58

What does Fitt's law deal with?

Answer 58

movement time

Question 59

What is reaction time a measure of?

Answer 59

brain processing speed