Postural_Control.ppt
Transcript of Postural_Control.ppt
Postural Control
DefinitionFunction
NeurophysiologySystems Model
DONG-EUI MEDCAL CENTERAHN BYUNG UG
The terms ‘balance’, ‘equilibrium’ and ‘postural control’are used as synonyms for the same concept of the mechanism by which the human body prevents itself from falling or loosing balance.
Ragnarsdottir 1996
Postural Control
‘controlling the body’s
position in space
for the dual purposes of
stability and orientation
Shumway-Cook and Woollacott 1995
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
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
BODY SCHEMA
▪ DEFINITION “A postural model one has of oneself, having to d
o with how one perceives the position of the body and the relationship of body parts. It is believed to be the basis for all motions”
(Barbara Zoltan 1991)
POSTURAL STABILITY
This involvesMaintaining the body’s center of mass within oundaries 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 Control . allows us to:
Maintain a variety of positions / postures Loose and regain midline - displacements Provide a reference frame and stability to
selectively move our eyes, head or limbs. Move from one position to another Carry out cognitive tasks whilst moving i.e. dual
tasks Function independently within a changing
environment
GRAVITY
Is a modality of afferent information.
It is a constant downward force with which man must develop the ability to interact in order to move selectively. Balance and agonistic activity is developed through exposure to gravity (BBTA 2002).
Systems control of posture
Ascending Descending 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)
Appropriate alignment of
body segments
Appropriate muscle activation
Orientate in midline
Interactive with BOS
Linear acceleration
against gravity
Aim to Optimise the System of postural Control
Musculoskeletal
Component
Neuromuscular
Synergies
Individual
Sensory
Systems
Sensory
Strategies
Internal
Representation
Anticipatory
mechanisms
Adaptive
Mechanisms
Systems
Model
of
Postural
Control
Musculoskeletal• Muscle length• Joint range of
movement• Compliance• Alignment• Strength
Neuromuscular• Normal tone• Reciprocal innervation• Patterns of movement / co
ordination• Appropariate level of activ
ation / timing / force
Anticipatory Mechanisms
Balance Strategies
SUMMARY
“Control of posture and movement 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 direction.”
CORE STABILITY
The co-activation of the abdominals and multifidus to stabilize the trunk and head during self initiated or facilitated limb activities