Chapter 8
Impaired Balance
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Balance
Foundation of coordination
Center of gravity (COG) constantly shifts over base
of support (BOS)
If sway exceeds limits of stability = compensation
If sway is within limits of stability = postural stability
Postural Stability
 Ability
to maintain the COG within stability
limits.
 Normal anterior/posterior sway – 12 degrees
from most posterior-anterior position.
 Lateral sway 16 degrees from side to side.
 If sway exceeds boundaries, compensation
is employed to regain balance. A smaller
envelope is created and tolerated.
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Physiology of Balance – Envelope
of Sway
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Contribution of Sensory Systems
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Somatosensory

Free nerve endings
 Ruffini endings
 Paciniform corpuscles
 Golgi-Mazzoni corpuscles
 Golgi ligament endings
 Muscle spindles
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Visual and Vestibular Neurophysiology
Visual
Provides sensory
information regarding
the position of the
head relative to the
environment, and
orients the head to
maintain level gaze.
Vestibular
Provides information
regarding orientation of
the head in space and
acceleration.
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Processing Sensory Information
Visual
Peripheral information
Vestibular
Cerebellum
Basal ganglia
Supplemental motor area
Motor output
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Response Strategies
(Ankle, Hip, Stepping)
Ankle Strategy




Used when displacements are small.
Displaces COG by rotation about the ankle joint.
E.g., Posterior displacement of COG –
Dorsiflexion at ankle, contraction of anterior
tibialis, quadriceps, abdominals.
Anterior COG displacement – Plantar flexion at
ankle, contraction of gastrocnemius, hamstring,
trunk extensors.
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Hip Strategy




Employed when ankle motion is limited, displacement is
greater, when standing on unstable surface that disallows
ankle strategy.
Preferred when perturbation is rapid and near limits of
stability.
Post. Displacement COG – Backward sway, activation of
hamstring and paraspinals.
Ant Displacement COG – Forward sway, activation of
abdominal and quadricep muscles.
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Stepping Strategy

If displacement is large enough, a forward or
backward step is used to regain postural control.
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Motor Learning
Cognitive Phase
What to do
Associative
Phase
How to do it better
Autonomous
Phase
Just do it
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Causes of Impaired Balance

Injury or disease of eyes, inner ear, peripheral
receptors, spinal cord, cerebellum, basal ganglia,
cerebrum, etc.
 Injury or damage to knee, ankle, hip, and back
 DJD
 CVAs, tumors, visual field loss
 Age
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Effects of Training On Balance

Improvements in balance measures
 Improvements in lower extremity strength
 Effective in reducing the effect of, or exposure to,
risk factors for falling in the elderly
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Examination and Evaluation of Impaired
Balance (3 categories)
1.
2.
3.
Balance during functional activities with or
without assistive devices.
Balance (static or dynamic) with or without use of
assistive devices.
Safety during gait, locomotion, or balance.
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Examination and Evaluation of
Impaired Balance

Standing with eyes open – fixed platform

Standing blindfolded – fixed platform

Sway-referenced vision w/fixed support

Normal vision w/sway-referenced support

Sway-referenced vision and support
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Six Balanced Testing Situations
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Activities for Treating Impaired Balance
Most important factor is determining cause of
impairment
Strength
Base
Motor control
Modulator element
Fear
Cognitive/affective
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Mode – Graduated Intervention

Begin with weight shifts on a stable surface
 Gradually increase sway
 Increase surface challenges (mini-tramp, etc.)
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Posture
Often includes “core” stability training to improve
COG control and sense of trunk posture
 Begin in supine or seated position
 Over sessions, use a variety of arm positions,
unstable surfaces, single leg stances, etc.

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Movement

Adding movement patterns to acquired stable
static postures increases balance challenge.
 Add ant./post. sway to increase stability limits.
 Trunk rotations and altered head positions alter
vestibular input.
 PNF techniques during trunk rotation.
 Stepping back/forward assists in re-stabilization
exercises.
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Dosage – Environment
Depends on patient’s situation
Elderly – most training, in clinic
 Progress to types of external environment patients
will face when they leave the clinic.
Active individuals – Balance activities may be carried
out at home or at local health club.
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Sequence
BOS – Advance from wide to narrow base
Posture – Stable to unstable posture (sway)
Visual – Closing of the eyes
COG – Greater disruption to elicit hip or stepping
strategy
Progress to more dynamic activities, unstable
surfaces, and complex movement patterns.
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Perturbation
Extrinsic
feedback
(e.g., mirrors)
Balance and
movement control
Intrinsic
Development of motor
strategies
Motor activity
Muscle
activity
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Contraindications and Precautions

Persons who are
inherently in balancedchallenged positions.

Eliminate obstacles or
unsafe objects from
exercise area.
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Summary

Balance is an important component of
coordination.

Aging is associated with balance impairment and
places the elderly at risk for falls.

Balance is a function of the triad of visual,
vestibular, and somatosensory systems.
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Summary (cont.)

Ankle strategies are used in response to small
perturbations.

Hip and stepping strategies counter larger
perturbations.

Treatment should be aimed at the cause –
biomechanical, sensorimotor, or both.
Copyright 2005 Lippincott Williams & Wilkins