L7/8: Balance theory & assessment Flashcards
Why is balance so significant in the elderly?
35% of persons aged >65 yrs will fall in 1 year, with poor balance as a primary risk factor
Great risk of falling
- Poor balance is a risk factor for falls
What does the dynamic system approach look like?
What are the changes to these systems with age that are important to balance control & that we can change??
What are the 4 effects of age on postural stability in quiet stance?
- increase in COP and COM motion with age (distance, velocity, frequency)
- decreased if co-contracting (sway less if co-contracting)
- Generally AP > ML
- More visually dependent (EC postural sway+)
Balance declines much ______ (earlier/later), no just 65 years old (eg. 32 yrs vs 43 yrs)
In a healthy older person, should be able to hold ____ stance with eyes ____ (open/closed) for 30 secs. There should be some deterioration and difficulty holding ____ stance with eyes ______(open/closed) for 30 secs.
tandem; open; tandem; closed
What are the 3 impacts of age-related balance?
- Quiet stance
- Functional movement
- Reactive control
What is the impact on quiet stance of age-related decreased somatosensation on balance?
Increased postural sway / COPE (reduced detection of COM position) particularly on foam / EC
What is the impact on functional movement of age-related decreased somatosensation on balance?
> errors – e.g. catch toe & trip
What is the impact on reactive movements of age-related decreased somatosensation on balance?
slower / less accurate / >overshoot
Length of time able to hold a stance ____ (increased/declines) as we age
declines
What is reactive control?
- Detect what movements are occurring
- How far travelling forward
- How to respond
What are 3 somatosensory age-related pathology?
- LL osteoarthritis: decrease jt position sense, increase/ decrease COPE in stance – consider impact of which joint
- Peripheral neuropathy (eg. diabetes): COPE in stance
- Csp pathology – neck pain, whiplash: disruption to Csp proprio - decrease quiet stance time.
What are 2 somatosensory interventions for balance issues?
- Retrain skill with practise:
- Cannot replace sensory organs if tissue is damaged (e.g. Peripheral neuropathy, scar tissue), but can retrain other LL somatosensors to compensate
- Compliant surfaces, particularly with EC
- Can improve in elderly
- Increase awareness of at risk situations, safety
What is the impact on quiet stance of age-related decreased vision on balance?
Increased sway as > reliance on somatosensors & these are likely to be reduced
What is the impact on functional movements of age-related decreased vision on balance?
> cautious (very tentative), errors, falls
What is the impact on reactive control of age-related decreased vision on balance?
min direct effects
What is contrast sensitivity?
Unable to see the step (vision affecting ability to balance)
Why is having visual issues a problem on balance? What can be done to improve balance?
Once vision deteriorates, unable to improve.
Therefore, must train somatosensation
What are 2 visual interventions for balance issues?
Minimal direct intervention
- Refer, raise awareness, practise at-risk situations
- Train somatosensory challenge safely
What is the impact on quiet stance of age-related decreased vestibular on balance?
increased postural sway with sensory conflict – on foam + EC and with central & peripheral vestibular dysfunction
What is the impact on functional movements of age-related decreased vestibular on balance?
overbalance during gait with head turns / brings on dizziness
What is the impact on reactive control of age-related decreased vestibular on balance?
slowed detection of head mvt
Several different intervention approaches depending on _____
deficit
What is an example of sensory conflict?
- Eg. stand on foam –> challenge somatosensation • Shut eyes –> no visual challenge other Rely on vestibular
What is the vestibular system?
- Detection of head movements
- If problem Slow detection of head movements
What are 5 impacts on quiet stance of age-related decreased cognitive functional on balance?
- decreased perceived + real stability limits
- (They think they are worse than they are They think they are better than they are)
- decreased ability to resolve sensory conflict
- Visual VS somatosensory VS vestibular
- Visual system tellling something contradictory compared to other systems (seen in periphery)
- On bus –> get off bus –> when bus moves again –> older person falls –> think they were on bus (movement of bus))
- more frequent sense of self-motion
- backward disequilibrium ( ○ Reduces limit of stability Think upright is further forward or backwards than normal)
- altered perception of vertical &fall backwards.
What are cognitive functional interventions for balance issues (quiet stance)?
can improve LOS, sensory integ., sense upright, raise awareness
What are 3 impacts on quiet stance + functional movements of age-related decreased cognitive functional on balance?
- attentional capacity decrease with age
- ability to dual/multi-task when one is a postural task decrease with age / balance impairment
- Restricted mvt due to fear of falling
What are cognitive functional interventions for balance issues (quiet stance/functional tasks)?
can change attention priority, improve dual tasking (Should train dual-tasking –> can improve
Simpler tasks –> complex tasks) when balancing / walking, improve confidence
What is attentional capacity?
Ability to do things more than once
What are 2 impacts on reactive control of age-related decreased cognitive function on balance?
- Slower responses, especially if choice reaction time – longer time in response selection
- Can improve with training
How to train reactive control?
Progress from simple to more complex
What is the impact on quiet stance of age-related decreased motor function on balance?
little impact
What is the impact on functional tasks of age-related decreased motor function on balance?
slower mvt with less power
What is the impact on reactive control of age-related decreased motor function on balance?
slower responses with smaller amplitude – because m activation timing delayed, altered co-ordination/patterning and amplitude reduced
What are 3 characteristics of steady-state control?
- Ongoing control of body balance / motion
- Most deficits here relate to detection &processing of sensory info, or determination of COM position
- Minimal demands placed on body wrt timing, scaling of activity
What are 5 characteristics of anticipatory control?
- Postural adjustments made in advance of voluntary movement to stabilize body
- Internally generated control
- Basal ganglia key role in mvt generation
- Timing, scaling & co-ordination of muscle activity critical
- Delayed onset of anticipatory activity:
- glut med in stepping
- hams in UL task
- ES in hip F
What are 2 features that increase the risk of falls?
- longer CRT
- delayed glut med in stepping
What are 2 ways we can influence risk of falls?
- Alter muscle timing: Delayed muscle activation –> increased risk of falls
- Impacting scaling of activity
What are 3 characteristics of reactive control?
- Rapid responses to external perturbation
- Automatic postural responses – delayed &reversal of distal ®proximal patterns with age
- Stereotypical strategies
- altered with age
- Timing, co-ordination & scaling of activity key to producing strategies
What are 3 strategies for balance perturbations?
- Hip
- Ankle
- Step
What are 5 age changes in reactive control?
- Delayed onset of automatic postural response
- Reversal of distal –> proximal patterns of activation
- More frequent co-contraction
- > variability in onset times
- More mixed postural response strategies
Usually, for perturbation strategies to regain balance, muscle activation occurs ____ (proximally/distally) to _____ (proximally/distally). However, during ageing, muscle activation occurs ____ (proximally/distally) to _____ (proximally/distally) and this _____(increases/decreases) risk of falls.
proximally; distally; distally; proximally; increases
What are 3 strategies of postural recovery?
- Stereotypical patterns of body segment motion to reduce degrees of freedom
- Relative to postural goals, the task, the environment
- Four major strategies theorized from AP motion
What is the ankle strategy?
Inverted pendulum
What strategy is this patient using?
Hip strategy (most movement here)
What strategy is this patient using?
Step strategy
What strategy is this patient using?
Ankle (possibly) but she is using grasp
What are 3 ML (side) strategies?
- Load/unload
- Step
- Crossover step
What is the ideal strategy for side ML perturbations?
Outwards step
What strategy do younger adults use for side ML perturbations? Why?
Able to detect the weight shift and take this outwards step
What strategy do older adults use for side ML perturbations? Why?
- Take too long to detect weight shift
- No longer able to unload the leg
- End up taking a cross overstep
What are 4 changes with age and pathology with musculo-skeletal system?
- decreased muscle strength, power / rate of torque development
- decreased muscle endurance
- decreased muscle length
- decreased joint ROM
What are the 6 reasons why we need to assess balance?
- determine functional limitations & impairments
- document functional level
- identify strategies used to achieve function
- prediction:
- eg falls risk, rehab outcome
- direct treatment
- patient feedback
What are the levels of assessment?
There is no one test that can record all information at all levels need to be perform multiple tests
What are 6 features of functional ability that are specific to balance tests?
- steady state
- anticipatory / ongoing control
- reactive control
- sensory system manipulation
- cognitive demand
- combination test batteries
There is no one test that can record all information at all levels need to be perform _____ tests
multiple
What are 4 ways to decide what tests to be used for balance level?
- Patient’s age, fxal level, impairments, limitations
- Resources available: time, equipment, assistance
- Function of the test
- Tests should be reliable, valid and sensitive