review dynamical systems theory explains change in systems that exchange energy with the surrounding...

Review

• Dynamical systems theory explains change in systems that exchange energy with the surrounding environment

• DST explains how behavior changes through self organization– typically no one teaches a child to run… – speed is the catalyst

Motor Development

Re-conceptualizing Developmental Change in Movement Patterns

Life Span Motor Development

Evolution of a Theory & Research Program

In the beginning...a clinician!

a knowledge of neurodevelopmental theory

a fascination with righting and equilibrium reactions

a love for movement analysis

Neurodevelopmental Theory

development is a process of reflex integration

lower level automatic behavior gives way to higher level volitional control

Spinal Level

Brain stem Level

Midbrain

Motor Ctx

Neurodevelopmental Theory

Progressive Positive Add Abilities End State Oriented

(maturity is the end state)

Neurodevelopmental Theory

CNS = Cause of Change

Biological Theory of Aging...

Regressive Negative Loss of Abilities End state oriented

(end state = death)

Life Span Theory

Development followed by Aging

Milani - Comparetti

Milani Comparetti = my personal Control Variable!

Change of State

Virginia... (1970s)

Wisconsin (1980s)

The Doctoral Experience

Roberton’s Component Model

Developmental Stages of Throwing

Reliability of assigning Stages

Developmental Change within Components of Body Action

Component Model of Development

Upper Limbs Axial Region Lower Limbs

Lawrence & Kuypers

Three descending control systems

medial system – controls axial region lateral system – controls proximal limb

movements in primate studies the lateral system allowed for

differentiated arm movements cortical system – controls distal movements

in primate studies allowed individuated finger movments

Straying into Systems models

Not just one big hierarchy Roberton was studying development in those

systems!

Applying Roberton’s Method

Taking it to a new task From Throwing to Righting

Learning the Research Process

Righting Reactions

Developed during 1st year of life Rolling to prone Up on hands and knees Into sitting Quadruped to kneeling Kneeling to Half Kneel Up to Stand

Righting Reactions

• Movements couple together to assume erect stance

• Foundation for Physical Independence

Righting Reactions

First Rotational movements then Symmetrical

But observations of young adults in PT school revealed all were not using symmetrical form

Studies of Righting

Rising to Standing from the Floor Young Adults

Why Young Adults?

variability in PT students impressive a very few showed symmetrical form when rising

Roberton examined variability to get stages of throwing

Lifespan perspective hypothesis: variation was “developmental”

Sequences

If person is in a stage he/she shows stable behavior characteristic of that stage

If a person is moving from one stage to another shows variable behavior characteristic of those

two neighboring stages

Studies of Righting

Rising to Standing from the Floor Young Adults

Variability continued to be impressive across 10 trialsDescribed action in each of three components of body

action able to identify neighboring stages for each body region

Really out on a Limb

Studies of Righting

Rising to Standing from the Floor Children

Age differences confirmed sequences of movement pattern development identified from adult patterns of variation

Component Model affirmed