BALANCE
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 2/39
Balance basics
Balance def.+ ability to maintain one’s
COM within the BOS in a given sensory
environment.Systems involved: MS, NM
Somatosensory,visual,and vestibular
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 3/39
Stabilizing postural responses
Postural control is maintained in a
cooperative manner
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 4/39
Faulty balance
Pathology in any system
Disruption between the potential
biomechanical and neurophysiologicconstraints
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 5/39
Performing A Comprehensive
Balance Exam
Interview Pt.
PMH
Social Hx Fall hx
Meds
Mental Status
Observation
Biomechanical Factors
Sensation
CoordinationVision
Cone of Stability
Motor CoordinationSensory Organization
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 6/39
Components of Postural Control
Limits of Stability: maximum angle from
vertical that is tolerated without the loss of
balance.Base of support: proportional with LOS
Height of COM is inversely proportional to
LOSSway
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 7/39
Sensory organization
Afferents provide information about body
position from 3 sources:
Somatosensory Visual
Vestibular
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 8/39
Somatosensory
Peripheral receptors and Joint receptors of
the foot and ankle
Detects motion of the body with respect to
the supporting surface
Detects motion of the body segments with
respect to each other
In impairment delayed responses of 20-30
msec
Role in scaling motor response to perturb.
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 9/39
Vision
Provides info about body position relative
to environment and moving environment
itself Most sensitive to low frequency stimulation
When moving more information is
processed
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 10/39
Vestibular
Two Functions:
Stabilizes the eyes during head movement to
assure steady gaze Maintains upright vertical body alignment
during head movement
Slowest of the three afferent systems
With conflicting info, vestibular system acts asa reference to ensure appropriate motorresponses
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 11/39
Central processing
Compares information from the threesystems
Intact processes result in the right motoroutput
Conflict: Sitting in a car and the car next toyou moves
visual identifies movement of environment
somatosensory perceives no change in position
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 12/39
Motor Coordination
Motor synergies maintain upright posture
Response depends on:
Latency of response Task dependence
Invariance of motor output
•
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 13/39
Automatic postural reactions
Def: Synergistic patterns of activation of LE
muscle in response to perturbation
Occur to maintain the COM within the BOS
Three synergistic motor responses are:
Ankle strategy
Hip strategy
Stepping strategy
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 14/39
Ankle Strategy
Used during quiet stance or secondary to
small perturbations on a normal support
surfaceM activity initiates distally at the ankle and
the radiates to the thigh and abdominal m,
producing torque at the ankle
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 15/39
Hip Strategy
Occurs in response to moderate perturbation
and or when the support surface is narrow
relative to the base of support, or whenthere is a direct perturbation to the pelvis.
I.E. Standing on a curb and being pushed. If
this didn’t occur, you would have to step off the curb
Muscle are activated in prox to distal
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 16/39
Stepping Strategy
Occurs when the LE and trunk cannot
maintain the COM with the BOS.
A step will Increase the BOS or realign it
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 17/39
Evaluating Automatic Postural
Reactions
Selection of the appropriate synergy
Latency of response
Amplitude of response or evidence of cocontraction
Visually assess the pts. motor response
when perturbatedI.D. the deficit so your intervention will beoptimal
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 18/39
Balance strategies
Selected in response also to sensory input expectation
prior experience practice
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 19/39
Adaptation and Flexibility
Assess motor synergies and determine
whether they are appropriate
Change the testing conditions by: Changing the support surface
Varying the magnitude of the perturbation
Pts. should be able to utilize a variety of strategies
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 20/39
Cognition
Attention is not required to maintain
balance
However we monitor the environment
Inattention to the environment may result in
being at risk for falls
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 21/39
Increased risk for falls: MS
impairment
Biomechanical limitations: ROM
M weakness
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 22/39
Neuromuscular impairment
Loss of m mass, dec. force production, and
decreased isokinetic jt. Mvt., impaired
motor learning, slower simple and complexvoluntary reaction times
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 23/39
Function of afferent system
Redundancy allows pts. with impairments
to maintain upright postural alignment
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 24/39
Somatosensory impairments
Elderly have 30-50% dec. vibration sense at
the ankle
Jt. Position sense is dec.
Peripheral Nerve conduction slows with age
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 25/39
Visual impairments
Dec. visual acuity, reduced visual fields,
increased susceptibility to glare, poor depth
perception, and reduction in peripheralfields are seen in the elderly
Dec. sensitivity to low spatial frequencies
results in the requirement for greatercontrast to detect spatial differences
successfully
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 26/39
Vestibular impairments
Loss of the vestibular system results in
appropriate use of the ankle strategy, but he
hip strategy is not used in the maintenanceof upright control
Declines in auditory and vestibular function
are widely documented in the elderly
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 27/39
Sensory organization testing
Also referred to as CTSIB.
6 conditions the pt is viewed for degree of
sway and maintenance of position.
Enables the examiner to select and weigh
conflicting sensory references
Misleading visual information is moreproblematic than absent vision
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 28/39
Balance Assessment Tools
Should have the following characteristics:
Reliable
Valid Sensitive
Specific
Ability to detect change over time
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 29/39
Assessment Tools
Measures of Standing Balance
Romberg: Assess the integrity of the neural
systems for individuals with neurosyphyllis.
Selective loss of the posterior columns. Pt stands, both feet together with narrow BOS arms
folded across chest.
Assess the amt. Of postural sway observed with
eyes open and then closed for 30 sec.
How long the pt. can maintain the position is timed.
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 30/39
One leg stance time
Document length of time pt. maintains
position
Important predictor of falls in the elderly
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 31/39
Functional Reach
DEF: Max distance a person can reach
forward while maintaining a fixed base of
support. Margin of stability can bedetermined.
Reach is the mean difference of initial and
final positions over three test trialsImpaired reach has been found predictive of
falls
C i d f
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 32/39
Computerized assessment of
postural control
Utilizes computerized measurement of
postural sway using a force platform
Effectively captures age associated changesinc. postural sway during static and
controlled leaning conditions.
Relationship to pt. functional performanceis not clearly established
E l f S O i ti
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 33/39
Eval of Sensory Organization
Roles of various sensory inputs on the
maintenance of postural control.
Computerized versions measure on stableand moving support surfaces
CTSIB
F ti l P f
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 34/39
Functional Performance
Measures
Evaluate functional performance of selected
tasks with performance criteria established
for scoring purposesRely on factors such as strength, flexibility,
motor control, and endurance to complete
the activities. Therefore they require morethan balance
Ex: TUG, Berg, Tinetti
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 35/39
Timed Up and Go
Measures the time required to rise from a
std. Chair, walk 3 meters, turn around,
return, and sit down.I ADLs scored task<10sec
<20 sec =cutoff functional ability.
>30 sec. Had impaired mobility and inc
risk for falls
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 36/39
BERG functional balance scale
14 tasks ranging in difficulty. Each item is
scored 0-4 based on specific criteria. Scale
allows grading to reflect improvement.< 45/56 increased risk for falls
Best single predictor of falls
Scores < or = to 40 present with almost100% risk of fall
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 37/39
Tinnetti (POMA)
2 sections balance and gait
Highest possible score 28
Scores <19 indicate high risk for falls
19-24 at risk, but not high risk
Attempts to quantify quality of gait
performance, captures higher level of
function. Pt may use an assistive device
T t t h
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 38/39
Treatment approaches
Any underlying impairment potentially modifiableshould be addressed
If not modifiable, compensation techniques and pt.
education should be the initial focus.
Practice reactions to improve reaction time
Comprehensive tx plans include: inc. pts. ability to
maintain postures, control movements of the
COM, respond to disturbances of the COM
T t t f B l
8/2/2019 Balance 4565
http://slidepdf.com/reader/full/balance-4565 39/39
Treatment of Balance
Dysfunction
1. Weakness: Progress from staticdynamic
2. Challenge on different surfaces, use visual
distortion, modify perturbations3. Vestibular emphasize appropriate strategy to
decrease symptoms.
4. Somatosensory change the external
environment add stimulus to inc. awarenessofextremities