Topic 3 – Emergence of Behavior:
3.1: Newell’s Model of Constraints
Newell’s Model of Constraints (1986)
This model accounts for individual variability. States that a movement is a result
of the dynamic interaction between individual, task and environmental
constraints. Changing one element may lead to a completely different movement
pattern. We must consider all dimensions to understand motor development and
how movement emerges. Constraints either permit a movement to emerge or
restrict a movement from occurring.
How can we manipulate things to push the system in the direction we want?
Manipulate the task, maybe intervene on functional constraints, surgery/
operations for structural constraints.
Individual constraints: a person’s own unique mental and physical characteristics.
May be structural (related to the structure of the body, e.g. height) or functional
(related to behavior, e.g. motivation). Structural are often long term constraints
and functional are often shortterm constraints.
A malformed limb introduces a structural constraint that gives rise to a different
movement then what would emerge if the limb were typically developed. It’s not
that the movement cannot be achieved. It just occurs through a different
What are some individual constraints for a child using the monkey bars?
Structural constraints include: arm length and strength while functional
constraints may include fear or lack of.
o Risk taking and challenges are critical.
Task constraints: constraints external to the body and consist of goals of the
movement, as well as the rules and equipment used. For example the rules of
soccer dictate that you cannot touch the ball with your hands, which places a task
constraint on the resultant movement. Another example is a car seat, however
equipment like this becomes problematic when we start restraining movements
too much. Environmental constraints: global constraints related to the world outside our
body, around us. These may be physical (e.g. temperature) or sociocultural (e.g.
girls & sport). For example the terrain a cyclist faces will introduce an
environmental constraint on the resultant movement.
3.2: Phases of Motor Development
The Developmental Continuum
Specialized Movement Phase
Fundamental Movement Phase
Rudimentary Movement Phase
Reflexive Movement Phase
Reflexive movement phase: involuntary, subcortically controlled movements that
are a relatively stereotypical response to a specific sensory stimulus. Grounded in
the idea that reflexes are maturationally determined. Reflexes are the first forms
of human movement.
Rudimentary movement phase: development of the basic forms of voluntary
movement typically mastered during infancy required for basic functioning.
Originally suggested to be maturationally determined, however now we know that
they are very much so influenced by the environment, cases of severe deprivation
provide evidence for the role the environment plays; characterized by a highly
predictable sequence of appearance, rate varies individually.
Fundamental movement phase: gross motor skills common to daily living and
should typically be mastered in early childhood. Exploration of a variety of
stabilizing (e.g. twisting), locomotor (e.g. hopping), and manipulation )e.g.
kicking) movements, first in isolation, then in combination.
Specialized movement phase: fundamental motor skills are progressively refined,
combined, and elaborated upon for application to task specific activities required
for daily living, recreation, and sport pursuits.
The Hour Glass Model The
represents motor skills from a developmental perspective. How do we get more
sand into the hourglass?
The heredity container has a lid, which represents a limited quantity of “sand”, or
in other words genetics play a limited role in motor skill development.
The environment container of sand does not have a lid and this can be interpreted
into the fact that there is not a limit to the magnitude of impact that the
environment can have on an individual’s motor skill development.
Hourglass model is used to represent lifelong motor development because this
process is made up of the period of progression as well as regression. We can get
more sand during the regression phase by lets say continuing to be physically
active, but at some point more sand will be leaking out than can be replaced.