Balance Flashcards
center of mass
- point at which distribution of mass is equal in all directions
- 2/3 of body height above BoS, slightly anterior to sacrum
when does center of mass change
with body position, independent of gravity
center of gravity
- vertical projection of CoM, gravity-dependent
center of gravity line
- anterior to ankle and knee joints
- at or posterior to hip joint
- trunk midline
- anterior to GH joint
- through external auditory meatus
base of support
area beneath a person that includes every point of contact that the person makes with the supporting surface
what keeps us balanced?
- 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
3 systems that consider balance
- vision
- somatosensory
- vestibular
with a firm/stable surface, what system is most dominant
- 70% somatosensory
- 20% vestibular
- 10% visual
with a compliant surface, what system is most dominant
- 60% vestibular
- 30% visual
- 10% somatosensory
anticipatory postural control
voluntary goal-directed movements in preparation for movement
- feed forward system
reactive postural responses
reaction to unplanned perturbations to balance resulting in displacement of CoG or moving the BoS
- feed back system
reactive strategies
ankle
hip
stepping
ankle strategy
- quiet standing
- counteract small pertubations
hip strategy
- counteract larger pertubations
- primary strategy for mediolateral control
stepping strategy
- when ankle and hip strategies fail
- ultimately increases base of support
sitting balance strategies
- 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
standing balance
- 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
intrinsic fall risk factors
- age
- impaired balance
- prior hx of falls
- fear of falling
- comorbidities/disease state
- medication side effects
extrinsic fall factors
- 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
how do we determine if a patient is “off-balance?”
- observation
- clinical hx taking
- clinical neurological examination
- subjective and objective outcome measures
what are subjective and objective outcome measures that can help determine if a pt is off balance
- 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
what percentage of falls occur at home
50-60%
fear of falling is common, what percentage of community-dwelling adults experience this
56-73%
fear of falling is a to falls
- a mjor risk factor
- associated with negative physical and psychosocial outcomes
are there individuals more likely to be afraid of falling
yes
- female
- reduced physical function
- use of walking aid
- hx of falling
- poor self-perceived health status
- environmental concerns
- depression/anxiety
