Part 1 Flashcards
vertigo and balance disorders affect ___% of the general population before 65 years
30%
What % of people over 70 years old report a significant fall/year with no major health or balance disturbance
40%
What % of people with balance disorders develop psychiatric disturbances (depression, anxiety)
66%
Over 75 what is the #1 reason for office visits and hospital admissions
Dizziness
What % of patients seen in primary care get no diagnosis for dizziness and what % of them get a prescription. What is prescription for?
50% seen get no diagnosis for dizziness but 70% get prescription for antivert (antivertigo meds)
what % of people 65 and older have experienced dizziness
80%
what % of children with SNHL have impairment of vestibular system
70%
Falls account for more than X amount of injuries in Canadians 65+
1/2
Injurious falls rank what position in leading cause of death in elderly population
6th
what are conditions that often occur with hearing limitations
mobility, aging and pain
what % of Canadians 15+ have hearing limitations and of this what % had the condition with additional limitations
5% and 87% had additional limitations associated with mobility aging and pain being most frequent
what risks do patients with Hearing loss face
reduced physical activity
What is balance (defined) 2 ways
- even distribution of weight allowing someone to stay upright and steady
- ability to maintain line of gravity through COG within BOS
how much money is spent on dizzy patients in Ontario yearly, cost in Canada annually and what is cost per patient a day, cost
31 million, 2 Billion annually $450
Center of Gravity (COG) defined
balancing equilibrium or pivoting point of body
- point where sum of all forces and force movements acting on body is zero
where is COG located
anterior to second sacral vertebra
what % of height can be measured from feet
55%
Base of Support (BOS) defined
area beneath person that includes every point of contact they make with supporting surface
- area b/w feet, including feet
what helps maintain stance better?
wider BOS, easier to drop COG within larger BOS than to project into narrower BOS
Line of gravity
imaginary vertical line passing through COG to BOS. through body of second sacral vertebra to point b/w feet when standing
What happens when we transition our BOS from static to dynamic
heel to heel distance will decrease as feet come towards midline
- toe to midline distance decrease (“toe in”)
overall effect= BOS narrows
when does a person become less balanced
when the BOS is narrowed because the chance of COG falling within BOS decreases
explain walking with COG and BOS
COG moves forward of BOS which is a precursor to walking and foot advances to extend the BOS
- COG moves than BOS follows
posture (defined)
postition or attitude of the body, stereotypical alignment of body/limbs
postural set
means of maintaining balance
- standing (static), walking (dynamic), sitting, lying etc.
-different postures for different things
what does posture do for us
- allows body to maintain upright alignment
- permits efficient movement patterns (min. energy exertion)
- allows joints to be loaded symmetrically (distributed evenly)
Postural control
act of maintaining achieving or restoring a state of balance during any posture or activity
postural control strategies
can be PREDICTIVE or REACTIVE and can involve a fixed support or change in support response
- when learning something new it is often inefficient but as we get better we can use the new postural control ex., ice-skating postural control developed
automatic activity
ex., walking and talking
- cognitive and energetic expense minimal
manual mode
switch into this mode when we are unexpectedly out of equilibrium to prevent fall
how is balance maintained
through postural alignment
- changes and adjustments made due to perturbations
maintain cog in bos
strategies to prevent falls
fixed support- leaning in when turning on skates
change in support- pushing skates to extend BOS
Limits of stability (LOS)
distance in any direction a subject can lean away from midline without altering BOS
what are the determinants of LOS
- firmness of BOS
- strength and speed of muscular responses
- range 8 degrees anteriorly & sides, 4 degrees posteriorly
- also depends on shoe size (BOS) and height
- taller= narrower LOS
components of system of balance model
stability at center surrounded by:
Musculoskeletal system
Goal/task orientation
Central set
Environmental organization
Motor coordination
Sensory organization
Musculoskeletal system
ROM joints
strength/power
sensation (pain)
abnormal muscle tone (hypertonia-spasticity and hypotonia)
Goal/task orientation
what is the nature of the activity/task
what are the goals
central set
past experiences have created motor programs which the CNS can select to fine tune a motor experience
- brains cant do fine tuning from sratch
environmental organization
nature of contact surface (texture, moving or stationary)
nature of “surrounds” regulatory features of environment ex., costume material- part of environment but not integral to task
motor coordination
movement strategies
feedback and feed forward control
adjustment/tuning of strategies
ex. ballerina using different programs and putting them together demonstrates good motor coordination
balance/postural control happens via 3 systems:
somatosensory, visual and vestibular
somatosensory disconnect causes
seasickness
visual/vestibular disconnect causes
contradictions; ex., stopped at red light car beside us moves gives illusion of movement. contradiction of movement from eyes but stillness in ears.
postural movement is used to
prevent falls
eye movement is used to
keep vision clear
reflex type response
is ms fast
consists of sensor processor and effector (motor response)
- upper level processing would slow things down
