Transcript POSTURAL CONTROL

Basic Bobath Course
Part I
Bergen March 1st-12th 2004
POSTURAL
CONTROL
THE BOBATH CONCEPT
MARY E LYNCH-ELLERINGTON.
POSTURAL CONTROL.
 The ability to control our body’s position against
and within the forces of gravity is fundamental
to everything we do.
 Almost every movement that an individual
makes is made up of both postural components
(which stabilise the body ) and prime mover
components (which relate to a particular
movement goal)

(Massion & Wooollacott 1996.)
AIMS
 To define and discuss normal postural
control.
 To develop links between the
development of postural control and the
systems control model.
 To analyse aspects of postural control in
a no of postural alignments for the
development of efficiency.
RELEVANCE
 Postural Control emerges from a
complex interaction of sensory and
musculoskeletal systems, integrated and
modified within the CNS and in response
to changing environmental conditions.
 The recovery of postural control post
stroke is considered to be a critical
component of the motor behaviour for
achieving independence in ADL.
WHAT IS THE TASK OF
POSTURAL CONTROL ?
To be able to control the body’s
position in space for the
purposes of both orientation
and stability.
POSTURAL ORIENTATION.
This involves
 The ability to maintain the appropriate
alignment between body segments
 The appropriate relationship between the body
and the environment.
 Requires establishing a vertical orientation to
counteract the forces of gravity.
 Creates a reference frame for perception and
action with respect to the external world.
POSTURAL STABILITY
This involves
 Maintaining the body’s centre of mass
within boundaries of space, referred to
as stability limits.
Stability limits are boundaries of an area
of space in which the body can maintain
it’s position without changing it’s base of
support.
STABILITY LIMITS.
 Stability limits are not fixed but may
change according to
the task
the individual
the environment.
Postural Action can be viewed as a
motor skill that emerges from the
interaction between the individual, the
task and the environment.
POSTURAL STABILITY.
 DIFFERENT TASKS WILL PUSH ASPECTS OF
STABILITY TO BEYOND THE STABILITY
LIMITS AND NECESSITATE A CHANGE IN
THE BASE OF SUPPORT.
 SOME TASKS SUCH AS DIVING TO SAVE A
FOOTBALL WILL PLACE GREATER
EMPHASIS ON ORIENTATION TO THE BALL
THAN ON STABILITY AND A CONTROLLED
FALL IS THEN ATTEMPTED.
POSTURAL CONTROL
 Postural Control may be less automatic than
previously thought. It has been suggested that
maintaining postural stability does require some
degree of attention…..research has similarly
demonstrated that attentional demands
increase as balance requirements of a task
increase
(Hunter & Hoffman 2001)
 Cognitive demands associated with balance
may contribute to the incidence of falling among
older adults.
(Brown et al 1999)
SYSTEMS CONTROL OF
POSTURE

.
DESCENDING
 ASCENDING
 PERIPHERAL
 “Posture is safeguarded by multiple inputs and
outputs. It reflects the care that evolution has
bestowed on the capability to adjust the body to
the direction of gravity, and parts of the body in
relation to each other.” (Brooks 1986)
PLAN.
 INTERNAL REPRESENTATION
 ROLE OF SENSORY INPUTS
 POSTURAL CONTROL STRATEGIES
 RECOVERY OF BALANCE
 CLINICAL TESTS OF BALANCE
 IMPROVING EFFICIENCY OF
POSTURAL CONTROL AND BALANCE.
INTERNAL REPRESENTATION
 It is thought that an internal
representation of body posture exists
within the CNS.
 This is often referred to as the
“ Postural Body Schema”.
 Body Schema incorporates body
geometry, kinetics, orientation with
respect to gravity.
BODY SCHEMA
 DEFINITION
“ A POSTURAL MODEL ONE HAS OF
ONESELF, HAVING TO DO WITH HOW
ONE PERCEIVES THE POSITION OF
THE BODY AND THE RELATIONSHIP
OF BODY PARTS…………
BODY SCHEMA
………..IT IS BELIEVED TO BE THE
BASIS OF ALL MOTIONS, FOR ONE
NEEDS TO KNOW THE PARTS OF THE
BODY AND THEIR RELATIONSHIP IN
ORDER TO KNOW WHAT, WHERE,
AND HOW TO MOVE ONESELF.
(Zoltan et al 1991)
BODY SCHEMA-GEOMETRY
 Body geometry-is thought to depend upon
proprioceptive 1a afferents from all parts of the
body.
“Recent findings suggest that trunk or hip inputs
may be more important in triggering human
balance corrections and that proprioceptive
input from the lower legs mainly helps with the
final shaping and intermuscular coordination of
postural and gait movements” (Allum 1998)
BODY SCHEMA-KINETICS
 Body Kinetics-has two aspects of
control
1. The nervous system’s evaluation of the
support conditions
2. The calculation of the inertia of different
body segments, used for providing an
accurate estimation of the centre of
gravity position.
LITERATURE REVIEW
 When a subject supports their weight
through their upper limbs the postural
reactions involve mainly the arm
extensor muscles in place of the leg
muscles. (Massion & Woollacott 1996)
 Cutaneous foot sole sensors and foot
muscle proprioceptors monitor amplitude
and direction of contact forces and are
important in upright stance control.
(Kavounoudias et al 1998)
BODY SCHEMA-ORIENTATION
 A top down orientation of the body is
given by the labyrinthine sensors which
allow detection of the head position in
space, relative to gravity.
 Visual information detects movement
and monitors head and body
displacement with respect to the external
world.
 Evidence exists for the presence of
graviceptors.
LITERATURE REVIEW
 “These graviceptors would monitor the force
vector exerted at each joint to oppose gravity
and this information would contribute to an
internal representation of the vertical axis.
A putative candidate for the monitoring of this
sensory information is the Golgi tendon organ
which measures the number of active motor
units at a given time in each muscle used in
postural control”
( Massion & Woollacott 1996 )
LITERATURE REVIEW
 “ There is preliminary evidence to
suggest that somatic gravity receptors,
originating from viscera within the trunk
exist in monkeys and in humans “
(Di Fabio & Emasithi 1997 )
 Recent research has argued for a
separate pathway in humans for sensing
body orientation in relation to gravity.
( Karnath et al 2000 )
MODERN LITERATURE
 ‘ Internal models are considered a
general neural process for resolving
sensory ambiguities, synthesising
information from disparate sensory
modalities, and combining efferent and
afferent information ’
(Perennou et al 2000)
POSTURAL CONTROL
STRATEGIES.
 REACTIVE ( Compensatory )
 PREDICTIVE ( Anticipatory )
 COMBINATION OF BOTH.
REACTIVE STRATEGIES
 ANKLE STRATEGY
 HIP STRATEGY
 STEPPING REACTIONS
 GRASP WITH HAND
 PROTECTIVE EXTENSION OF THE
UPPER EXTREMITIES.
PREDICTIVE STRATEGIES
 ANTICIPATORY POSTURAL
ADJUSTMENTS DURING VOLUNTARY
MOVEMENT
 RIGHTING AND EQUILIBRIUM
REACTIONS
POSTURAL ADJUSTMENTS
CENTRAL
COMMAND
POSTURAL
DISTURBANCE
POSTURAL
ADJUSTMENT
EQUILIBRIUM & RIGHTING
REACTIONS
 Equilibrium reactions consist of minute
postural adjustments which allow
maintenance of a desired posture.
 When greater perturbation necessitates
visible activity is seen. The response of
the body is to extend on the weight
bearing side and flex on the other.
 Rotation may be seen within the body
axis.
( Mayston 2001)
EQUILIBRIUM & RIGHTING
REACTIONS
 In the mature adult Righting Reactions
cannot be separated from Equilibrium
Reactions.
 Righting & Equilibrium Reactions allow
the loss and regaining of midline
through appropriate head and trunk
activity within the equilibrium response.
 In efficient subjects these reactions are
observed in all sequences of movement
e.g. sitting to lying, walking etc.
RECOVERY OF BALANCE
 Postural control strategies can become
more efficient and effective with training
and practice ( Horak et al 1997. )
 Somatosensory cues are a powerful
orientation reference for improved
control of upright stance ( Jeka 1997. )
RECOVERY OF BALANCE
 KEY QUESTIONS.
 Trained separately or as part of the task
or goal ?
 Practiced simultaneously ?
RETICULOSPINAL SYSTEM
 MEDIAL
 LATERAL
CORE STABILITY
 THE CO-ACTIVATION OF THE
ABDOMINALS AND MULTIFIDUS TO
STABILISE THE TRUNK AND HEAD
DURING SELF INITIATED OR
FACILITATED LIMB ACTIVITIES
VESTIBULOSPINAL SYSTEM
 Vestibular
 Midline
 Position and motion of the
head
 Control of posture and tone
 Somatosensory
 Visual
 Automatic postural
responses
 Cutaneous-amplitude and
direction of contact forces
important for locomotion.
 Control stance
 Signals position and movt of
head with respect to
surrounding objects
VESTIBULOSPINAL SYSTEM
 CONTRIBUTES TO HEAD ON BODY
STABILISATION.
 EXCITES THE ANTIGRAVITY
MUSCULATURE – POSTURE
SPECIFIC.
 AUGMENTS EXTENSION IN
LOCOMOTION.
MEASUREMENT
CLINICAL SCALES
 The Berg Balance Scale
 The Functional Reach Test
 Timed Tasks (e.g. single leg stance)
 The Postural Assessment Scale for Stroke
(PASS)
PHYSIOLOGICAL ASSESSMENT
 Posturography
 Force platforms.
SUMMARY
 “Control of posture and movemnt
requires initiation and planning at the
highest level, control and updating from
the middle level, and execution and
regulation of the task at the lowest level.
However it must be stressed that
interaction between these levels is
constant and ongoing, providing
information in both directions. “
(Edwards 1996)
PRACTICAL
 POSTURAL ORIENTATION
 CONTROL OF STABILITY LIMITS
 ALIGNMENT & STRENGTH
REFERENCES
Allum J, Bloem B, Carpenter M, Verschuuren J, & Honegger
F (2002) “ Triggering of balance corrections and
compensatory strategies in a patient with total leg
proprioceptive loss “ Experimental Brain Research, Vol.
142,No 1, p 91-107.
Di Fabio R & Emisithi A (1997) “ Aging and the mechanisms
underlying head and postural control during voluntary
motion” Physical Therapy, Vol. 77, No 5, p458-475.
Edwards S (1996) “ Neurological Physiotherapy: A Problem
Solving Approach, Churchill Livingstone, London.
Horak F, Henry S, & Shumway-Cook A (1997) “ Postural
Perturbations: New Insights for Treatment of Balance
Disorders” Physical Therapy, Vol.77, No.5,p 517.
Hunter M and Hoffmann M (2001) “Postural Control, Visual
and Cognitive manipulations” Gait and Posture, Vol.13,
No. 1, p 41-48.
Jeka J (1997) “ Light touch contact as a balance aid”
Physical Therapy, Vol.77, No. 5, p 476-487.
Karnath H, Ferber S & Dichgans J (2001) “ The neural
representation of postural control in humans “
Proceedings of the National Academy of Sciences of the
United States of America, Vol.97 No.25, p13931-132936.
Kavounoudias A, Roll R & Roll J (1998) “ The plantar sole is
a dynamometric map for human balance control” Neuro
Report, Vol. 9, No. 14, p 3247-3252.
Mayston M (2001) “Problem solving in Neurological
Physiotherapy: setting the scene in Edwards S (Ed)
Neurological Physiotherapy: A Problem solving approach.
Churchill Livingstone London.
Perennoiu A, Leblond C, Amblard B, Micallef J, Rouget E,
Pelissier J (2000) “The polymodal sensory cortex is
crucial for controlling lateral stability “ Evidence from
Stroke. Brain Research Bulletin April
Shumway-Cook A & Woollacott M (1995) Motor control
Isbn 0683077570.
Zoltan,Siev & Freishtat (1991) The Adult stroke Patient A
Manual for Evaluation and Treatment of Perceptual and
Cognitive Dysfunction. 2nd Edition N.Jersey Slack INC.