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Transcript of Muscular weakness, proprioceptive deficits, and range of motion deficits may challenge a persons...
Regaining Postural Stability and Balance
Rehabilitation Techniques for Sports Medicine and Athletic
Training William E. Prentice
Introduction
Muscular weakness, proprioceptive deficits, and range of motion deficits may challenge a persons ability to maintain their center of gravity (COG)› May lead to loss of balance
Balance is the single most important element dictating movement strategies
Dynamic process involving multiple neurological pathways
Introduction
Joint position sense , proprioception, and kinesthesia are vital to all athletic performance requiring balance
Ability to balance and maintain postural stability is essential to an athlete who is acquiring or reacquiring complex motor skills
Postural control system
Complex process involving sensory and motor components
Most daily activities such as, walking, climbing stairs, throwing a ball, require static foot placement with controlled balance shifts
Balance should be considered both a static and dynamic process
Postural control system
Impaired balance is a result of one or a combination of two reasons
› Position of COG relative to base of support is not accurately sensed
› Automatic movements required to bring COG to a balanced position are not timely or effectively coordinated
Postural control system
Position of the body in relation to gravity and its surroundings is sensed by combining visual, vestibular and somatosensory (proprioceptive)inputs
Balanced movements also involve motions of the ankle, knee, and hip joints› Primary mechanisms for controlling balance occur
in joints of the lower extremity Postural control system operates as a
feedback control circuit between brain and the musculoskeletal system
Somatosensory input
Mechanoreceptors transmit messages to brain through sensory nerves in spinal cord› Helps to control proprioception or
body/joint position
Provides information concerning the orientation of body parts to one another and to the support surface
Balance & Closed Kinetic Chain
Balance is the process of maintaining the COG within the body's base of support
Within kinetic chain each moving segment transmits forces to every other segment along chain› Maintaining equilibrium or balance is associated
with injuries along the closed kinetic chain Injuries to any one of the joints or corresponding
muscles along kinetic chain can result in loss of appropriate feedback for maintaining balance
Control of Balance
Human body is a tall structure on a relatively small base› COG is quite high, just above pelvis
Somatosensory input is preferred sense for balance› i.e. : feet in contact with support surface
and detection of joint movement
Control of Balance
Visual input› Measures orientation of the eyes and head in
relation to surrounding objects› If eyes are closed balance becomes more
difficult Vestibular input
› Sensory system that is leading contributor to response to movement and sense of balance
› Sends signals, primarily to neural structures that control our eye movement, and to muscles that keep us upright
Proprioception & Kinesthesia
Proprioception: ability to determine the position of a joint in space
Kinesthesia: ability to detect movement› Mediated by mechanoreceptors found in
muscle and joints and by cutaneous, visual and vestibular input
Proprioception & Kinesthesia
Joint mechanoreceptors› Found in ligaments, capsules, menisci,
labra and fat pads Sensitive to change in shape of joint
structures and rate and direction of movement of joint
Most active at end ranges of motion
Proprioception & Kinesthesia
Muscle mechanoreceptors› Found in muscles and tendons
Muscle spindles and Golgi Tendon Organs Muscle spindles sensitive to changes in length of muscle
Golgi tendon organs sensitive to changes in tension
Assessment of Balance
Subjective Assessments: Romberg's & Balance Error Scoring System (BESS)
Romberg's test› Feet together, arms out to side, and eyes
closed› Positive test: sway or fall to one side› indicates loss of proprioception
Assessment of Balance Balance Error Scoring System (BESS)
› 3 stances: double , single, and tandem Completed 2 x each: Once on firm
surface and once on unstable surface (Foam pad)
Total of 6 trials Hands on iliac crest and eyes closed
In SL ex. Non stance leg held at 20-30 degrees hip flexion and 40 to 50 degrees of knee flexion
Assessment of Balance
BESS Assessment Continued
20 second test begins when eyes close
Single leg stance on non-dominant leg (NDL) and NDL is in the rear for tandem stance
Upon losing balance athlete returns to testing position as quickly as possible
Assessment of Balance
Balance Error Scoring System (BESS)› Scoring
1 point added for each error that occurs Hands lifted off iliac crest Opening eyes Step, stumble or fall Moving hip into > 30 degrees of flexion or
Abduction Lifting forefoot or heel Remaining out of testing position >5 seconds
Higher scores represent poor balance
Assessment of Balance
Dynamic balance test include functional reach test, timed agility, figure 8’s, carioca, or hop test› Ability to maintain upright posture while
moving
Assessment of Balance
Advancements in technology have provided equipment to quantitatively assess and train dynamic balance› Mostly computer -interfaced force- plate
technology› Potential to assess possible
abnormalities that might be associated with injury and help create appropriate training programs
Injury & Balance
Stretched or damaged ligaments may fail to provide adequate neural feedback› May contribute to decreased
proprioceptive mechanisms, and thus decreased balance
› Increased postural sway and balance instability contributed to neurological factors and biomechanical factors after injury
Balance Training
Rehab program, especially for lower extremities must include exercises to improve balance and postural equilibrium› Any injury can cause disruption at some
point between COG and base of support› If neglected can lead to reinjury, decreased
performance, or other injuries
Balance Training
5 general rules› Safe, yet challenging› Stress multiple planes of motion› Incorporate multisensory approach› Begin with static, bilateral stable surface
and progress to dynamic, unilateral, and unstable surface
› Progress toward sport specific activity
Balance Training
Balance Exercises› Static: COG maintained over fixed base of
support while on stable surface
› Semi-dynamic: Maintain COG over fixed base on moving
support or unstable surface Person transfers their COG over a fixed base
of support on stable surface through range and/or directions
Balance Training
Balance Exercises› Dynamic: maintenance of COG over
moving base of support Usually stable surface, but could be unstable Base of support always changing position so
COG is forced adjust with each movement
› Functional Same as dynamic, but add sport specific
tasks
Balance Training
Phase I› Can be initiated once athlete can bear
weight on the extremity› Static, non ballistic exercise› Hard firm surface› Bilateral to unilateral (double leg to single
leg)› Eyes opened to eyes closed› Progress to unstable surface, perturbations
(taps or movement) Overload or stress somatosensory system
Balance Training Phase II
› Transition of static to semi-dynamic & dynamic ex. Important for running, jumping, and cutting
athletes Progress only if sufficient healing has occurred and
ROM, muscle strength and endurance is adequate Balance through movement
Controlled hip and knee flexion and smooth return to stabilization position
Progress to added resistance and more difficult movement patterns
Balance Training Phase III
› Dynamic & Functional exercises Slow speed to fast speed Low force to high force Controlled to uncontrolled activities
› Jumping or hopping activities Bilateral to unilateral Single plane to multi-plane Exercises may differ between athletes
Be sport specific
Conclusion
Balance and postural stability critical to athletic performance and injury prevention
A rehabilitation program must include functional exercises that incorporate balance and proprioceptive training › Prepare athlete for return to activity› Failure address balance problems may
predispose athlete to reinjury and injury› Use imagination, be creative› Use sport specific tasks