Lecture 8

Question 1

evidence found from Collins and Deluca (1993) supports what model?

Answer 1

Open and closed loop control

Question 2

Sway is allowed to….

Answer 2

travel relatively unchecked within a specific boundary (feedforward)

Question 3

When the COM approaches a particular limit…

Answer 3

a corrective response is made (feedback)

Question 4

Collins and deluca found that over shorter time periods of sway

Answer 4

COP was allowed to drift, promoting an open loop system

Question 5

Collins and deluca found that over longer periods of sway…

Answer 5

position was corrected and brought back to the central region

Question 6

Evidence found by van Emmerick and van Wegen(2002) support?

Answer 6

Time to stability boundaries
average time to stability was higher in young adults compared to older adults, suggesting larger amplitudes of sway are seen and more time is spent on the edge of stability

Question 7

The nervous system may be attuned to assess (in terms of balance)

time

Answer 7

How long it is going to be before COM gets to the limit

Question 8

Evidence found from Carpenter et. al. supports what model of static balance control

Answer 8

Exploratory sway model

Question 9

The negative feedback loop control model when the COM is externally stabilized suggests?

Answer 9

Corrective COP displacements should be reduced accordingly
Carpenter et. al. found evidence to disprove this

Question 10

experimental protocol for carpenter et. al.

Answer 10

instruction was to stand as still as possible while attached to backboard apparatus with wheels to control sway externally
measured forces, moments, and kinematics
dependant variables were COP RMS and COM angular dispalcement

Question 11

What did Carpenter et. al. find in their experiment

experiment where people were strapped to bike wheels

Answer 11

with external stabilization of sway, large amplitude low frequencies were seen and the system starts to shift, Large increase in COP RMS seen

Question 12

T/F, sway is only controlled with negative feedback

Answer 12

false

Question 13

Variability of COP may be used to…

Answer 13

ensure a certain quality and volume of sensory information

Question 14

sway can be used to…

Answer 14

measure how different factors influence balance control

Question 15

one may have vestibular deficits, and ___ sway may be needed

Answer 15

more, may be needed to. compensate and provide more information

Question 16

T/F larger sway doesn’t necessarily always mean bad balance control?

Answer 16

True
van Emmerick and van Wegen (2002) asked community to change their perspective on sway and balance control, suggest that healthier individuals have lots of sensory noise to provide info to CNS