Transcript Chapter 8: Regaining Stability and Balance

Balance lecture& Postural
Equilibrium
Dr.Afaf A.M Shaheen
lecture 11
RHS 322
 Factors affecting balance
 Muscular weakness
 Proprioceptive deficits
 ROM deficits
Terminology
 Balance - Process of maintaining body’s CoG (Center of
Gravity) within base of support
 Ability to align body segments against gravity to maintain or
move the body within the available base of support without
falling .
 Body’s CoG rests slightly above the pelvis
 Strength is emphasized before proprioception in rehab
because strength influences balance
 Postural equilibrium - broader term that incorporates alignment
of joint segments
 Maintaining CoG within the limits of stability (LOS)
Terminology
 Proprioception – body’s ability to transmit position sense,
interpret information & respond consciously/unconsciously
to stimulation
 Coordination – smooth pattern of activity is produced
through a combo of muscles acting together with
appropriate intensity & timing
 Agility – ability to control the direction of a body or
segment during rapid movement
Postural Control System
 3 Components of the system
 Sensory detection of body motions
 Visual
 Vestibular
 Somatosensory inputs
 Integration of sensorimotor information within the CNS
 Execution of musculoskeletal responses
 Balance is both a static & dynamic process
Control of Balance
 Tall body vs. Small base of support
 Balance relies on network of neural connections
 Postural control relies on feedback
 CNS involvement
 Sensory organization
 Determines timing, direction & amplitude of correction based on
input
 System relies on one sense at a time for orientation
 Muscle coordination
 Collection of processes that determine temporal sequencing &
distribution of contractile activity
 Sensory Input
 Vision
 Measures orientation of eyes & head in relation to
surrounding objects
 Helps maintain balance
 Vestibular
 Provides information dealing with gravitational, linear &
angular accelerations of the head with respect to inertial
space
 Somatosensory
 Provides information concerning relative position of body
parts to support surface & each other
Somatosensation = Proprioceptive system
Specialized variation of the sensory modality of
touch, encompassing joint sense (kinesthesia) &
position
Process
•Input from mechanoreceptors
•Stretch reflex triggers activation of muscles
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
 Body position in
relation to gravity is
detected by sensory
input
 Balance movements
involve a number of
joints
 Ankle
 Knee
 Hip
 Coordinated movement
along kinetic chain
Prentice, 2004, 4th ed.
 Postural sway
 Deviation from Center of Pressure, Balance &
Vertical Force (CoP, CoB, or CoF)
 Determined using mean displacement, length of sway
path, length of sway area, amplitude, frequency and
direction relative to CoP
 Symmetry - Ability to distribute weight evenly
between 2 feet in upright stance
Balance Disruption
 Balance Deficiencies - Inappropriate interaction among 3 sensory
inputs
 2 Factors that Disrupt Balance
 Position of CoG relative to base of support is not accurately
sensed
 Automatic movements required to maintain the CoG are not
timely/effective
 In the event of contact, the body must be able to determine
what to do in order to control CoG
 Joint mechanoreceptors initiate automatic postural response
Selecting Movement Strategies
during Balance Disruption
 Joints (Ankle, Knee & Hip) involved
allow for a wide variety of postures that
can be assumed in order to maintain CoG
 Instance of musculoskeletal
abnormality
 Damaged tissue result in reduced joint ROM
causing a decrease in the LOS & placing
individual at a greater risk for fall
 Research indicates that sensory proprioceptive
function is affected when athletes are injured
 Subjective
Assessment of
Balance
Assessment
 Romberg Test –
traditional assessment
 Balance Error
Scoring System
(BESS)
Google Images
Prentice, 2004,
4th ed.
 Semi-dynamic & dynamic tests
 functional reach tests
 timed agility tests
 carioca
 hop test
 Timed T-band kicks
 Timed balance beam walks (eyes open &
closed)
 Objective Assessment
 Balance systems
 Provide for quantitative assessment & training static & dynamic balance
 Easy, practical & cost-effective
 Utilize to assess:
 Possible abnormalities due to injury
 Isolate various systems that are affected
 Develop recovery curves based on quantitative measures in order to
determine readiness to return
 Train injured athlete
 Computer interfaced force-plate technology
 Vertical position of CoG is calculated
 Vertical position of CoG movement = indirect measure of postural
sway
 Force plate
measures
 Allows for static &
dynamic postural
assessment
 Single or double leg
stance, eyes opened
or closed
Prentice, 2004, 4th
ed.
 Dynamic stability - Ability to transfer vertical
projection of CoG around a stationary supporting base
 Perception of safe limit of stability
 Athlete should maintain their CoP near A-P and M-L
midlines
Injury & Balance
 Stretched/damaged ligaments fail to provide adequate neural
feedback, contributing to decreased balance & proprioception
 May result in excessive joint loading
 Could interfere with transmission of afferent impulses
 Alters afferent neural code conveyed to CNS
 Decreased reflex excitation
 Caused via a decrease in proprioceptive CNS input
 May be the result of increased activation of inhibitory interneurons within the
spinal cord
 All of these factors may lead to progressive degeneration of joint
& continued deficits in joint dynamics, balance & coordination
 Ankles
 Joint receptors believed to be damaged during injury to lateral ligaments
 Knee Injuries
 Ligamentous injury has been shown to alter joint position
detection
 Head Injury
Balance Training
 Vital for successful return to competition from lower
leg injury
 Possibility of compensatory weight shifts and gait changes
resulting in balance deficits
 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
Rules of Balance Training
 Exercise must be safe & challenging
 Stress multiple planes of motion
 Incorporate a multisensory approach
 Begin with static, bilateral & stable surfaces & progress to
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dynamic, unilateral & unstable surfaces
Progress towards sports specific exercises
Utilize open areas
Assistive devices should be in arms reach early on
Sets and repetitions
 2-3 sets, 15 → 30 repetitions or
 10 of the exercise for 15 → 30 seconds later on in the program
Classification of Balance Exercises
 Static  CoG is maintained over a fixed base of support, on a stable
surface
 Semi-dynamic
 Person maintains CoG over a fixed base of support while on
a moving surface
 Person transfers CoG over a fixed base of support to
selected ranges and or directions within the LOS, while on
a stable surface
 Dynamic
 Maintenance of CoG within LOS over a moving base of
support while on a stable surface
 Functional
 Same as dynamic with inclusion of sports specific task
 Phase I
 Non-ballistic types of drills
 Static balance training
 Bilateral to unilateral on both
involved & uninvolved sides
 Utilize multiple surfaces to
safely challenge athlete &
maintaining motivation
 With & without
arms/counterbalance
 Eyes open & closed
 Alterations in various sensory
information
 Incorporation of multiaxial
devices
 Train reflex stabilization &
postural orientation
Prentice, 2004, 4th
ed.
 Phase II
 Transition from static to dynamic
 Running, jumping and cutting – activities that require the
athlete to repetitively lose and gain balance in order to
perform activity
 Incorporate when sufficient healing has occurred
 Semi-dynamic exercised should be introduced in the
transition
 Involve displacement or perturbation of CoG
 Bilateral, unilateral stances or weight transfers involved
 Sit-stand exercises, focus on postural
Bilateral Stance Exercises
Prentice, 2004,
4th ed.
 Unilateral Semi-
dynamic exercises
 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
 Balance Shoes
Prentice, 2004, 4th
ed.
 Phase III
 Dynamic & functional types of exercise
 Slow to fast, low to high force, controlled to uncontrolled
 Dependent on sport athlete is involved in
 Start with bilateral jumping drills – straight plane jumping patterns
 Advance to diagonal jumping patterns
 Increase length and sequences of patterns
 Progress to unilateral drills
 Pain & fatigue should not be much of a factor
 Can also add a vertical component to the drills
 Addition of implements
 Tubing, foam roll
 Final step = functional activity with subconscious dynamic
control/balance
Phase III Exercises
Prentice,
2004, 4th
ed.
The dynamic proprioceptive re-education consists of
seven stages:1. Slow exercises followed by quicker movement
2. Exercise with limited effort followed by exercises
requiring greater strength
3. Exercises requiring volition, followed by exercises
done freely
4. Progress from walking to jogging
5. Running and sprinting
6. Jumping and changes of direction
7. Twirling and twisting around the injured or operated
knee
Balance and control proprioceptive exercises
1.
2.
3.
4.
Stand on one leg.
Stand on one leg with eyes closed.
Stand on one leg – throw and catch a ball.
Stand on one leg – bend and straighten knee
5. Stand on one leg- pick up item from floor.
6. Hold knee dip – throw and catch a ball.
7. Stand on one leg – move other leg to side,
front and back.
8. Push up onto toes (2 legs) and hold.
9. Push up onto toes with eyes closed.
10.Push back onto heels, balance and hold.
11. Push up on toes on one leg.
 Walking proprioceptive exercises
1.
2.
3.
4.
5.
6.
Walk forward along a straight line.
Walk on tip toes along straight line.
Walk backwards along straight line.
Side step along straight line.
Walk sideways crossing one foot over other (Cariocas).
Walk fast in one direction, quickly changing direction at
intervals.
Running proprioceptive exercises
1.
2.
3.
4.
Run fast in one direction.
Run backwards and do sidesteps.
Fast crossovers (Cariocas).
Run in figure of eight – make it smaller and smaller.
5.
6.
7.
8.
9.
Hopping on spot
Hop forwards and backwards – stop between hops.
Hop in zigzags.
Hop on and off step
Do triple jump - run, hop, jump and land.
• Balance and strength exercises are combined by incorporating light external
forces and increasing the level of difficulty for balancing while
strengthening the muscles required for dynamic stabilization
The Fitter is useful for weight
shifting
• Plyometrics begin with low-impact hopping, progressing
to double-leg bounding, and finally single-leg hopping.
References
 Prentice, W.E. (2004). Rehabilitation Techniques for
Sports Medicine and Athletic Training, 4th ed.,
McGraw-Hill
 Houglum, P.A. (2005). Therapeutic Exercise for
Musculoskeletal Injuries, 2nd ed., Human Kinetics.
 Kisner, C. & Colby, L. (2002). Therapeutic Exercise
Foundations & Techniques, 4th ed., F.A. Davis.
 http://www.google.com - Images