posture and balance

Question 1

what is balance

Answer 1

quiet standing - involving keeping the centre of mass within the base of support

Question 2

what allows the body to stand in the inverted pendulum model of human standing

Answer 2

using torque provided by active calf muscles

Question 3

what is the equation for inverted pendulum stance

Answer 3

F= MG
force= mass x gravitational constant

Question 4

center of gravity or mass is what

Answer 4

a point the mean position of the matter in a body or system

Question 5

what is the centre of pressure

Answer 5

a point on a surface through the resultant force applies total pressure force

Question 6

Centre of pressure oscillates forward and back to maintain…

Answer 6

centre of mass - sway can be quantified by com

Question 7

standing is a what control process

Answer 7

sensorimotor

Question 8

what are the 3 things for why we sway

Answer 8

sensory estimation
motor output
external and internal perturbations - b

Question 9

what 5 things keep us upright

Answer 9

vision
proprioception
vestibular apparatus
touch
efference copy of motor command and prediction

Question 10

2 different frequency control .. are…

Answer 10

slow / low frequency - visual control
fast/ high frequency for vestibular input

Question 11

removing visual information cause’s the body to..

Answer 11

sway

Question 12

quality of visual input can also effect

Answer 12

sway

Question 13

distant visual information is useless for balance - t or f and why

Answer 13

t - no retinal motion

Question 14

what is motion parallax

Answer 14

objects appear to move relative to each other
depending on focus point

Question 15

objects appear to move relative to each other when we sway bc it

Answer 15

provides more information

Question 16

the largest reduction is observed when foreground and background scenery are .

Answer 16

present together and furthest apart

Question 17

what is perturbing visual input- visual vection

Answer 17

a false sense of motion induced by a false scene

Question 18

what is this an example of
watching an adjacent train depart the station

Answer 18

visual vection

Question 19

visual vection may impact what

Answer 19

sway and standing control / posture

Question 20

subjects sway in the direction of

Answer 20

visual scene movement

Question 21

the brain interprets forward scene motion as … and creates …..

Answer 21

backward body motion ….a compensatory forward response

Question 22

effect of predictability on visual response

experimental triggers motion unexpectantly what response

Answer 22

big sway

Question 23

ankle creates torque around calf to help prevent the body doing what

Answer 23

toppling forward

Question 24

changes in muscle stiffness represent changes in what

Answer 24

muscle reflexes

Question 25

removal of sensory information effects what

Answer 25

posture

Question 26

muscle stiffness and balance is reduced with less

Answer 26

sensory information (visual and no vestibular)

Question 27

ankle torque increases as the angle of ankle …

Answer 27

increases

Question 28

the stiffness in the ankle is too low to permit

Answer 28

passive standing - standing without active modulation of emg

Question 29

balance involves keeping com within

Answer 29

base of support

Question 30

sway occurs mostly at which joint

Answer 30

ankle

Question 31

sway arises from

Answer 31

lack of sensory information