Regaining Postural Stability and Balance

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14 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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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


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


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


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


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


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 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


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



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: 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



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


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


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



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


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



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
o
r Abduction


Lifting forefoot or heel


Remaining out of testing position >5 seconds


Higher scores represent poor balance


Dynamic balance test include functional
reach test, timed agility, figure 8’s,
carioca, or hop test


Ability to maintain upright posture while
moving


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


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


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


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 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 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


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


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


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



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