Week 12- Balance Flashcards
PART 1
PART 1
What are 3 important terms when talking about Balance?
- Center of Mass (CoM)
- Center of Gravity (CoG)
- Base of Support (BoS)
What is the point at which distribution of mass is equal in all directions and changes with body position? It is independent of gravity.
CoM (center of mass)
Where is the CoM generally located?
2/3 of body height above BoS, slightly anterior to sacrum (6in above belly button)
What is the vertical projection of CoM and is gravity dependent?
CoG (center of gravity)
- The CoG is located _______ to the ankle and knee joints.
- The CoG is located ___ or ________ to the hip joint, trunk midline.
- The CoG is located ________ to the GH joint.
- The CoG goes ________ the external auditory meatus.
- anterior
- at or posterior
- anterior
- through
What is the area beneath a person that includes every point of contact that the person makes with the supporting surface?
BoS (base of support)
What exactly is balance?
Control of the CoM over the BoS.
Balance is divided into postural _______, ________, and ___________.
- control
- stability
- orientation
What is postural control?
Ability to control body position in space within and outside our BoS. (balance)
What is postural stability?
Ability to control CoM and CoG over BoS in varying sensory environments.
What is postural orientation?
Ability to maintain position with respect to gravity.
What 6 things keep us balanced?
- Limits of Stability
- Anticipatory Control
- Reactive Responses
- Sensory Organization/Integration
- Stability During Gait
- Biomechanical
PART 2 AND 3
PART 2 AND 3
What are the 3 main systems involved in the CNS processing for balance?
- Somatosensory
- Vestibular
- Visual
How is our semsorimotor integration of the 3 systems split based on whether we are standing on a firm/stable surface or a compliant surface?
Firm/Stable -70% Somatosensory -20% Vestibular -10% Visual Compliant -60% Vestibular -30% Visual -10% Somatosensory
Firm/Stable Surface:
- __% Somatosensory
- __% Vestibular
- __% Visual
- 70% Somatosensory
- 20% Vestibular
- 10% Visual
Compliant Surface:
- __% Vestibular
- __% Visual
- __% Somatosensory
- 60% Vestibular
- 30% Visual
- 10% Somatosensory
As we age, we become _______ reliant for balance.
visually
__________ input is the dominant sense for upright postural control and is most active in triggering automatic postural responses in almost all cases.
Somatosensory
Visual input is split into ______ (_______) vision and __________ (__________) vision.
- Central (foveal)
- Peripheral (ambient)
_______ vision is largely conscious while ________ vision is largely subconscious.
- Central (foveal)
- Peripheral (ambient)
_________ input provides information to the CNS about position and motion of the head.
Vestibular
Vestibular input is unique in its ability to distinguish _____ motion from _________ motion.
- self
- environmental
Somatosensory, Visual, and Vestibular Input act on a __________.
continuum
When changes in the environment occur, what happens to the 2 systems of balance? What is this called? Give an example.
- Available, accurate, and useful information is “upweighted,” whereas unavailable, inaccurate, or less-useful information is “downweighted”.
- Multisensory Reweighting
- Walking at night, vision is downweighted while somatosensory is upweighted.
We will also see multisensory reweighting after _________ injury.
neurological
When reweighting occurs, ________ is inevitably impacted.
balance
CNS processes this weighted sensory input to allow for descending commands to motor and neuromuscular systems to allow for our body to be in one of what 3 states?
- Steady State (quiet balance)
- Anticipatory Postural Control (activate in advance)
- Reactive Postural Responses (perturbation recovery)
Anticipatory Postural Control:
- Motor planning based on prior ____________ to avoid losses of balance.
- Involves the _________ system and _______ control.
- Voluntary _____-__________ movements in preperation for movement.
- experiences
- feedforward, cerebellar
- goal-directed
Do Anticipatory Postural Control or Reactive Postural Responses act faster?
Anticipatory Postural Control
What muscles act the quickest in regards to anticipatory control in the UE and LE?
- UE =Biceps
- LE = Gastrocnemius
Limits of Stability:
- Postural sway is _______, gentle, automatic and involuntary A and P oscillations.
- Normal = __ degrees in all directions.
- normal
- 8 degrees (cone of stability)
What happens if our CoM gets outside of the Limits of Stability?
We begin to lose balance and need to react.
Reactive Postural Responses:
- Reaction to unplanned ___________ to balance resulting in displacement of CoG or moving the BoS.
- Feedback system (dependent on fast _______ and ______ responses)
- perturbations
- fast sensory and motor responses
- Reactive Postural Responses = __________
- Anticipatory Postural Control = __________
- feedback
- feedforward
What are the 3 main reactive strategies?
- Ankle Strategy
- Hip Strategy
- Stepping Strategy
- What reactive strategy is used to counteract large perturbations?
- What reactive strategy is used to counteract small perturbations?
- What reactive strategy is used when ankle and hip strategies fail?
- Hip
- Ankle
- Stepping
- Ankle Strategy = _____ to ______ muscle recruitment
- Hip Strategy = ______ to ______ muscle recruitment
- distal to proximal
- proximal to distal
Biomechanical Considerations:
- A direct relationship between _______/______/_____ and balance has been well documented in literature.
- Ankle _____ and _______ strength are independent predictors of functional performance.
- PF strength of ______ affected balance and function in older adults.
- Weakness of hip and knee _________ was associated with increased likelihood of employing a multi-step strategy to recover from balance perturbations.
- Exercise has shown to have a __________ effect on fall risk in older adults.
- strength/power/endurance
- PF and DF
- big toe
- extensors
- proactive
Stability During Gait:
- Goal is controlled forward transference of _____.
- __% of our BoS during gait is in DLS.
- __% of our BoS during gait is in SLS.
- CoM
- 40%
- 60%
Adding a __________ load to a balance test is a great progression for patients.
cognitive
What happens when our strategies fail?
FALLS
PART 4
PART 4
Why are we so concerned with falls?
Falls are DANGEROUS
- Can lead to severe orthopedic injuries (back and hip fractures)
- Neurological injuries, TBI, Spinal Cord
What is the most common cause of TBI (traumatic brain injuries)?
Falls
Fall risk factors can be _______ or _________. List examples of each.
Intrinsic
- AGE
- impaired balance
- prior Hx of falls
- fear of falling
- Comorbidities/Diseased state
- Medications side effects
Extrinsic
- type of surface
- slippery surface
- obstacles, stairs, curbs
- poor lighting
- footwear
- poorly fitted AD and/or orthotics
- recreational drugs, alcohol
Why is balance such a huge issue for aging patients?
- __ in __ Americans falls each year
- Falls are the leading cause of fatal injury and the most common cause of nonfatal trauma-related hospital admissions in ____________.
- Community dwelling incidence __-__% with injury rate of __-__%.
- Fall-related injuries lead to 15% re-hospitilization in ____ month post-discharge.
- 1 in 4
- older adults
- 30-40%, 10-15%
- first
Does aging directly cause bad balance?
NO, rather aging negatively impacts crucial systems involved in our balance, which leads to higher risk for falls.
Balance Strategies and Aging:
- _______ __ _________ tend to decrease.
- With age, tend to see larger and more delayed ___________ postural adjustments.
- Higher levels of _______ _______ were correlated with better anticipatory responses.
- Fear of falling found to increase anticipatory postural adjustment durations.
- Direct correlation between muscle fatigue and slowed reactive postural responses in older adults.
- Increased dominance of _____ strategy, even with smaller CoM displacements.
- Limits of Stability
- anticipatory
- physical fitness
- hip
Visual Changes and Aging:
- Presbyopia
- ______ senstivity
- _________ dark adaptation
- Difficulty shifting ______ (far/near)
- Slower visual ________ time
- Difficulty distinguishing ______
- Loss of ____________ vision
- glare
- reduced
- focus
- reaction
- color
- peripheral
What are some common vision pathologies seen with aging?
Cataracts, glaucoma, macular degeneration, diabetic retinopathy
What are the functional implications of visual changes with balance?
- Higher risk for falls at night or in reduced lighting.
- At risk to trip due to peripheral vision loss.
- Slower reaction time = reduced reactionary strategies for balance.
Does aging break down our somatosensory system?
No
Vestibular Changes and Aging:
- Loss of ____ cells in SCC and otoliths
- ___________ of otolithic membranes
- Microvascular ________
- Reduction of vestibular and cerebellar neurons and nuclei
- Reduced effectiveness of _____
- hair
- calcification
- ischemia
- VOR
What are the functional implications of vestibular changes with balance?
- Less capacity for detection of rotation and gravity-related positions
- Reduced gaze stabilization with head movements
- Increased postural sway
- Sensory substitutions can mask deficit more effectively than with other impaired systems
NMS/MSK Changes and Aging:
- Decrease in # of type I and II fibers (__>__)
- Decrease in # of ___s as well as maximal voluntary muscle activation
- Muscle performance (strength, power, endurance) decreases __% every year after age 60
- Decrease in peak _______ muscle power
- Increase in agonist/antagonist __-________ during volitional movement
- Increased muscle connective tissue leads to decreased _________
- Increased risks of __________
- II>I
- MUs
- 3%
- anaerobic
- co-activation
- flexibility
- osteoporosis
What are the functional implications of NMS/MSK changes with balance?
- Reductions in strength, power and muscle endurance have all been tied to balance deficits
- High prevalence of OP results in more risk of fracture when falls occurs
- Postural changes lead to changes in COM/COG/BOS
- Greater axial stiffness and reduced flexibility
Cognitive Changes and Aging:
- Conceptual reasoning, memory, and processing speed __________ with time
- Decreased use of strategies to improve learning and memory
- Reduced selective and divided __________
- Gradual reduction in visual constructional skills
- Research has shown that concept formation, abstraction, and mental flexibility decline with age, especially after age 70
- decrease
- attention
What are the functional implications of cognitive changes with balance?
- Dual Task
- Carry over
How do we determine if a patient is “off-balance”?
- Observation (postural alignment, weight distribution, functional task analysis)
- Clinical History Taking
- Subjective Outcome Measures
- Objective Outcome Measures (cut-off scores, MDC, MCID)
- What is a cut-off score?
- What is MDC?
- What is MCID?
- Score in which we can say they are at risk if scored below.
- When met, you can determine it was met not by chance.
- Amount of change where you will see improvement in function.
What is the most common subjective outcome measure for falls?
Activity-Specific Balance Confidence Scale (ABC)
Describe the Activity-Specific Balance Confidence Scale (ABC).
- 16-item questionnaire (0-100 score)
- Measure of balance confidence in performing various activities without losing balance or experiencing a sense of unsteadiness
- Evaluates vestibular and non-vestibular balance tasks as well as functional mobility
What is a 2nd subjective outcome measure for falls?
Tinetti Falls Efficacy Scale
Describe the Tinetti Falls Efficacy Scale.
- 10-item questionnaire with each item is rated from 1 (very confident) to 10 (not confident at all)
- Assesses perception of balance and stability during activities of daily living as well as non-vestibular balance tasks, functional mobility, life participation, and self-efficacy
- Cut-Off Scores: >80 increased risk of falling, >70 indicates fear of falling
What are some domains of balance?
- Limits of Stability
- Anticipatory Postural Control
- Reactive Postural Responses
- Limits of Stability involves ________ tasks.
- What are some outcome measures for limits of stability?
- reaching
- Functional Reach Test, Multidirectional Reach Test
- Anticipatory Postural Control involves activities that require ______ rotation such as what?
- What are some outcome measures for anticipatory postural control?
- trunk rotation such as reaching, twisting, stepping, kicking, punching
- 5TSTS, BBS, Mini BESTest, 4 Square Step Test
- Reactive Postural Responses are activities that require a patient to respond ________ such as what?
- -What are some outcome measures for reactive postural responses?
- respond such as start/stop activities
- Push/Pull Test, Mini BESTest, DGI/FGA, Tinetti
What are some outcome measures we can use to assess sensorimotor integration?
- Romberg Test
- Sensory Organization Test (SOT)
- Clinical Test for Sensory Interaction in Balance (CTSIB) (foam and dome test)
What are the APTA EDGE 6 Core Outcome Measures?
- ) Berg Balance Scale
- ) Functional Gait Assessment
- ) Activities-Specific Balance Confidence Scale (ABC)
- ) 10MWT
- ) 6MWT
- ) 5TSTS
What is the point of the 6 Core Outcome Measures?
- All encompassing look at someones balance, postural control, and functional mobility after a neurological event.
- All 6 can be tied to balance.
- Anticipatory Postural Control is a ____________ system that closely coincides with motor control and accurate muscle grading.
- Principles of __________ are crucial with traning this aspect of balance. (repitition, specificity, transferance)
- feedforward
- Neuroplasticity
