Balance

Question 1

center of mass

Answer 1

• point at which distribution of mass is equal in all directions
• 2/3 of body height above BoS, slightly anterior to sacrum

Question 2

when does center of mass change

Answer 2

with body position, independent of gravity

Question 3

center of gravity

Answer 3

• vertical projection of CoM, gravity-dependent

Question 4

center of gravity line

Answer 4

• anterior to ankle and knee joints
• at or posterior to hip joint
• trunk midline
• anterior to GH joint
• through external auditory meatus

Question 5

base of support

Answer 5

area beneath a person that includes every point of contact that the person makes with the supporting surface

Question 6

what keeps us balanced?

Answer 6

• biomechanical
• stability during gait
• sensory organization/integration
• reactive responses
• anticipatory control
• limits of stability
• cognition
• behavior
• neuromuscular synergies
• endurance
• MSK input
• internal representation
• sensory strategies

Question 7

3 systems that consider balance

Answer 7

• vision
• somatosensory
• vestibular

Question 8

with a firm/stable surface, what system is most dominant

Answer 8

• 70% somatosensory
• 20% vestibular
• 10% visual

Question 9

with a compliant surface, what system is most dominant

Answer 9

• 60% vestibular
• 30% visual
• 10% somatosensory

Question 10

anticipatory postural control

Answer 10

voluntary goal-directed movements in preparation for movement
- feed forward system

Question 11

reactive postural responses

Answer 11

reaction to unplanned perturbations to balance resulting in displacement of CoG or moving the BoS
- feed back system

Question 12

reactive strategies

Answer 12

ankle
hip
stepping

Question 13

ankle strategy

Answer 13

• quiet standing

- counteract small pertubations

Question 14

hip strategy

Answer 14

• counteract larger pertubations

- primary strategy for mediolateral control

Question 15

stepping strategy

Answer 15

• when ankle and hip strategies fail

- ultimately increases base of support

Question 16

sitting balance strategies

Answer 16

• somatosensory input –> thighs, buttocks, feet
• stability –> less degrees of freedom (3)
• direction of control stability –> A/P most stable, LOB tends to primarily occur laterally
• anticipatory postural control –> gastroc, quads, glutes
• reactionary strategies –> reaching

Question 17

standing balance

Answer 17

• sometosensory input –> ankle/foot
• stability –> more degrees of freedom (6)
• direction of control stability –> lateral more stable than A/P
• anticipatory postural control –> gastroc, trunk extensors
• reactionary strategies –> ankle, hip, step

Question 18

intrinsic fall risk factors

Answer 18

• age
• impaired balance
• prior hx of falls
• fear of falling
• comorbidities/disease state
• medication side effects

Question 19

extrinsic fall factors

Answer 19

• type of surface
• slippery surface
• obstacles, stairs, curbs
• poor lighting or sudden changes in lighting
• footwear
• poorly fitted AD and/or orthotics
• recreational drugs, alcohol

Question 20

how do we determine if a patient is “off-balance?”

Answer 20

• observation
• clinical hx taking
• clinical neurological examination
• subjective and objective outcome measures

Question 21

what are subjective and objective outcome measures that can help determine if a pt is off balance

Answer 21

• cut off scores give you a normative value
• minimum detectable change proves it wasn’t due to chance
• meaningful clinically important difference carries over into fxn, can make a goal since connects to their functional level

Question 22

what percentage of falls occur at home

Answer 22

50-60%

Question 23

fear of falling is common, what percentage of community-dwelling adults experience this

Answer 23

56-73%

Question 24

fear of falling is a to falls

Answer 24

• a mjor risk factor

- associated with negative physical and psychosocial outcomes

Question 25

are there individuals more likely to be afraid of falling

Answer 25

yes - female - reduced physical function - use of walking aid - hx of falling - poor self-perceived health status - environmental concerns - depression/anxiety