Transcript Chapter 8: Regaining Stability and Balance

Chapter 8: Regaining
Stability and Balance
Jenna Doherty-Restrepo, MS, ATC, LAT
Rehabilitation Techniques in Athletic Training
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved
Balance
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Factors that impact balance
– Muscular weakness
– Proprioceptive deficits
– ROM deficits
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Balance is critical in dictating movement
strategies within the closed kinetic chain
Vital component in rehabilitation
– Proprioception and Kinesthesia
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Postural Control System
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Components
– Sensory detection of body motions (Feed-forward)
– Execution of musculoskeletal responses (Feedback)
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Balance is a static and dynamic process
Disrupted balance occurs due to two factors
– Position of CoG relative to base of support is not
accurately sensed
– Automatic movements required to maintain the CoG
are not timely or effective
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved
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Body position in relation
to gravity is sensed by
– Visual
– Vestibular
– Somatosensory inputs
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Balance movements
involve a number of
joints
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Ankle
Knee
Hip
Coordinated movement
along kinetic chain
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Control of Balance
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Postural control relies on feedback
CNS involvement
– Sensory organization
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Determines timing, direction and amplitude of correction
based on input
System relies on one sense at a time for orientation
– Muscle coordination
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Collection of processes that determine temporal sequencing
and distribution of contractile activity
Balance deficiencies
– Inappropriate interaction among 3 sensory inputs
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Patient that is dependent on one system may be presented
with inter-sensory conflict
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
Sensory Input
– Somatosensory
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Provides information concerning relative position of body
parts to support surface and each other
– Vision
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Measures orientation of eyes and head in relation to
surrounding objects
Role in maintenance of balance
– Vestibular
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Provides information dealing with gravitational, linear, and
angular accelerations of the head with respect to inertial
space
Minor role when visual and somatosensory systems are
operating correctly
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Proprioception/Kinesthesia
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Specialized variation of the sensory modality of
touch, encompassing joint sense and position
Process
– Input is received from mechanoreceptors
– Stretch reflex triggers activation of muscles about a
joint due to perturbation
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Results in muscle response to compensate for imbalance and
postural sway
– Muscle spindles sense stretch in agonist, relay
information afferently to spinal cord
– Information is sent back to fire muscle to maintain
postural control
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Closed Kinetic Chain
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Balance
– Process of maintaining body’s CoG within base of
support
– CoG rests slightly above the pelvis
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Kinetic chain
– Each moving segment transmits forces to every
other segment
– Maintaining equilibrium involves the closed
kinetic chain
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Foot = distal segment (fixed beneath base of support)
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved
Balance Disruption
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Body must be able to determine what strategy
to utilize in order to control CoG
– Joint mechanoreceptors initiate automatic postural
response
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Selection of Movement Strategy
– Joints involved allow for a wide variety of postures
that can be assumed in order to maintain CoG
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Forces exerted by pairs of opposing muscles at a joint to
resist rotation (joint stiffness)
Resting position and joint stiffness are altered independently
due to changes in muscle activation
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
Ankle Strategy
– Shifts CoG by maintaining feet and rotating body as
a rigid mass about the ankle joints
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Gastrocnemius or tibialis anterior are responsible for
torque production about ankle
Anterior/posterior sway is counteracted by gastrocnemius
and tibialis anterior, respectively
– Effective for slow CoG movements when base of
support is firm and within LOS
– Also effective when CoG is offset from center
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved

Hip Strategy
– Relied upon more heavily when somatosensory loss
occurs and forward/backward perturbations are
imposed
– Aids in control of motion through initiation of large
and rapid motions at the hip
– Effective when CoG is near LOS perimeter and when
LOS boundaries are contracted by narrower base of
support
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Stepping Strategy
– Utilized when CoG is displaced beyond LOS
– Step or stumble is utilized to prevent a fall
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Balance and Injury
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Damaged tissue results in reduced joint ROM
causing a decrease in the LOS
– Greater risk for fall
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Research indicates that sensory proprioceptive
function is affected when athletes are injured
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Assessment of Balance
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Subjective Assessment
– Traditionally assessed via the Romberg Test
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Feet together, arms at side, eyes closed
Loss of proprioception is indicated by a fall to one side
Balance Error Scoring System (BESS)
– Utilizes three stances
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Double, single, tandem on both firm and foam surfaces
– Athletes are instructed to remain motionless with
hands on hips for 20 seconds
– Unnecessary movements and correction of body
position are counted as ‘errors’ (max score = 10)
– Results are best utilized if compared to baseline data
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved
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Assessment of Balance
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Semi-dynamic and Dynamic Balance tests
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Functional reach tests
Timed agility tests
Carioca
Hop test
Timed T-band kicks
Timed balance beam walks (eyes open and closed)
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Injury and Balance
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Stretched/damaged ligaments fail to provide
adequate neural feedback, contributing to
decreased proprioception and balance
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May result in excessive joint loading
Could interfere with transmission of afferent impulses
Alters afferent neural code conveyed to CNS
Decreased reflex excitation
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Caused via a decrease in proprioceptive CNS input
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Ankle Injuries
– Joint receptors damaged during injury to lateral
ligaments
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Results in Articular Deafferentation
– Diminished signaling via afferent pathways
– Reason behind balance training in rehabilitation
– Orthotic and bracing intervention
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Enhance joint mechanoreceptors to detect perturbations and
provide structural support for detecting and controlling sway
– Chronic ankle instability
– Recovery of proprioceptive capabilities
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Instability vs. Deafferentation
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Knee Injuries
– Ligamentous injury alters joint position detection
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ACL deficient subjects with functional instability exhibit this
deficit (persist to some degree after reconstruction)
May also impact ability to balance on ACL deficient leg
– Mixed results have been presented with static testing
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Isometric strength could compensate for somatosensory deficits
Definition of functionally unstable may vary
– Role of joint mechanoreceptors with respect to end range and the
far reaches of the LOS
– More dynamic testing may incorporate additional
mechanoreceptor input
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Results may be more definitive
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Head Injuries
– Balance has been utilized at a criterion variable
– Additional testing is necessary in addition to balance
and sensory modalities
– Postural stability deficits
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Deficits may last up to three days post-injury
Result of sensory interaction problem - visual system not
used effectively
– Objective balance scores can be utilized to determine
recovery curves for making return to play decisions
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Balance Training
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Vital for successful return to competition
from lower leg injury
– Possibility of compensatory weight shifts and
gait changes result in balance deficits
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Functional rehabilitation should occur in the
closed kinetic chain – nature of sport
Adequate and safe function in the open
chain is critical = first step in rehabilitation
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Rules of Balance Training
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Exercise must be safe and challenging
Stress multiple planes of motion
Incorporate a multisensory approach
Begin with static, bilateral, and stable surfaces and
progress to dynamic, unilateral, and unstable
surfaces
– Progress towards sports specific exercises
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Utilize open areas
Assistive devices should be within arms reach
Sets and repetitions
– 2-3 sets, 15 sec.  30 sec. repetitions
– 10 sets, 15 sec.  30 sec. repitions
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Classification of Balance
Exercises
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Static
– CoG maintained over fixed base of support on stable surface
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Semi-dynamic
– CoG maintained over fixed base of support while on a moving
surface
– CoG transferred over fixed base of support in selected ranges
and/or directions within the LOS while on a stable surface
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Dynamic
– CoG maintained within LOS over a moving base of support
while on a stable surface (involve stepping strategy)
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Functional
– Same as dynamic with inclusion of sports specific task
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Phase I
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Non-ballistic types of drills
Static balance training
Bilateral to unilateral
Utilize multiple surfaces to
safely challenge athlete
With and without
arms/counterbalance
Eyes open and closed
Alterations in various
sensory information
ATC can add perturbations
Incorporation of multiaxial
devices
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Bilateral Stance Exercises
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Phase II
– Transition from static to dynamic
– Running, jumping, and cutting
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Activities that require the athlete to repetitively lose and
gain balance in order to perform activity
Incorporate only when sufficient healing has occurred
– Semi-dynamic exercises should be introduced in
the transition
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Involve displacement or perturbation of CoG
Bilateral, unilateral stances or weight transfers
Sit-stand exercises, focus on posture
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– Unilateral Semidynamic exercises
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Emphasize controlled
hip flexion, smooth
controlled motion
Single leg squats, step
ups (sagittal or
transverse plane)
Step-Up-And-Over
activities
Introduction to
Theraband kicks
Balance Beam
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Phase III
– Dynamic and functional types of exercise
– Start with bilateral jumping drills (straight plane)
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Advance to diagonal jumping patterns
Increase length and sequences of patterns
– Progress to
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Unilateral drills, vertical drills
Addition of implements
– Tubing, foam roll, etc…
– Final step = functional activity
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Subconscious dynamic control/balance
(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved
Phase III Exercises
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