Theories of motor control

Meant for Final year students Physiotherapy.

1. Dr. SuvarnaGanvir
Professor
DVVPF’s College of Physiotherapy,
Ahmednagar

2. Introduction.
Understanding the nature of movement.
Theories of motor control.
Reflex theory
Hierarchical theory
Motor programming theory
Systems theory
Dynamic action theory
Ecological theory

3. Motor control is defined as the ability to regulate or
direct the mechanisms essential to movement.
Therapeutic intervention is often directed at changing
movement or increasing the capacity to move.
Therapeutic strategies are designed to improve quality
and quantity of posture and movements essential to
function.

4. T
Task.
E
Environment.
I
Individual.
M
Movement.
Understanding the nature of movement.

5. C
cognition
A
action
P
perception
I
Factors within the individual that constrain movement.

6. M
mobility
M
manipulat
ion
S
stability
Task constraints on movement.

7. R
regulatory
N
Non regulatory
Environmental constraints on movement

8. Value of theory to practice:
Framework
for
interpreting
behavior.
Guide for
clinical
action.
New ideas:
dynamic and
evolving.
Working
hypothesis
for
examination
and
intervention.

10. The reflex can not be considered the basic unit of behavior.
The reflex theory does not adequately explain and predict
movement that occurs in the absence of a sensory stimulus.
The theory does not explain fast movements.
The concept that a chain of reflexes can create complex
behaviors fails to explain the fact that a single stimulus can
result in varying responses depending on context and
descending commands.
It does not explain the ability to produce novel movements.

11. If chained or compounded reflexes are the basis for
functional movement, clinical strategies designed to
test reflexes should allow therapist to predict function.
A patient’s movement behavior would be interpreted
in terms of presence or absence of controlling reflexes.
Retraining motor control for functional skills would
focus on enhancing or reducing the effect of various
reflexes during motor tasks.

12. The nervous system is organized as an hierarchy.
Hierarchical control is defined as organizational control
that is top down.
The current concept describing hierarchical control
within the nervous system recognize the fact that each
level of nervous system can act on other level depending
on the task.

13. It can not explain the dominance of reflex behavior in
certain situations in normal adults.
E.g. stepping on a pin.

14. Abnormalities of reflex organization have been used by
many clinicians to explain disordered motor control in the
patient with a neurologic disorder.
The reflex hierarchical theory was used to describe
disordered movement following a motor cortex lession.
Bobath sated that “ the release of motor responses
integrated at lower levels of from restraining influences of
higher centers, especially that of the cortex, leads to
abnormal postural reflex activity. ”

15. The concept of a central motor pattern, or motor
program, is more flexible than the concept of a reflex.
As it can either be activated by sensory stimuli or by
central processes.
The term motor program may be used to identify a
central pattern generator, that is a specific neural circuit.

16. The motor program cannot be considered to be the sole
determinant of action.
Thus the motor program concept does not take into
account the fact that the nervous system must deal with
both musculoskeletal and environmental variables in
achieving movement control.

17. Explanations for abnormal movement have been
expanded to include problems resulting from
abnormalities in central pattern generators or in higher
levels of motor programs.
In patients whose higher level of motor programming
are affected, motor program theory suggest the
importance of helping patients relearn the correct rule
for action.

18. Berstein, a Russian scientist, was looking at the nervous
system and body in a whole new way.
He suggested that one can not understand neural
control of movement without an understanding of the
characteristics of the system you are moving and the
external and internal forces acting on the body.
In describing the body as a mechanical system, berstein
noted that we had many degrees of freedom that need
to be controlled.

19. As a solution to the degree of freedom problem, he
hypothesized that hierarchical control exists to
simplify the control of the bodies multiply degrees of
freedom.
He believed that synergies play an important role in
solving the degree of freedom problem.

20. It does not focus heavily on the interaction of the
organism with the environment, as do some other
theories of motor control.

21. It stresses the importance of understanding the body as
a mechanical system.
When working with a patient who has CNS deficit, the
the therapist must be careful to examine the
contribution of impairments in the musculoskeletal
system, as well as the neural system, to overall loss of
motor control.

22. Self organization is a fundamental dynamic systems
principle.
It says that when a system of individual parts come together,
its elements behave collectively in an ordered way. There is
no need for a higher center issuing commands in order to
achieve coordinated action.
This principle applied to motor control predicts that
movement could emerge as a result of interacting elements,
without the need for specific command or motor programs
within the nervous system.

23. This theory suggests that the new movement emerges
due to a critical change in one of the systems called a
control parameter.
A control parameter is a variable that regulates change in
the behavior of the entire system.
An important concept in describing movement from a
dynamic action theory perspective is that of attractor
state.
Attractor states may be considered preferred patterns of
movement used to accomplish common activities of daily
life.

24. The presumption that the nervous system has a fairly
unimportant role and that the relationship between the
physical system of the animal and the environment in
which it operates primarily determines the animal’s
behavior.

25. Movement is an emergent property.
i.eit emerges from the interaction of multiple elements
that self organize based on certain dynamic properties
of the elements themselves.
It means that alterations in the movement behavior can
be explained in terms of physical principles rather than
necessarily in terms of neural structures.

26. The ability to use perceptions to guide action emerges
early in life.
Gibson, stated that perception focuses on detecting in
the information in the environment that will support the
action necessary to achieve the goal.
The ecological perspective has broadened our
understanding of nervous system function from that of a
sensory/motor system, reacting to environmental
variables, to that of perception/action system that
actively explores the environment to satisfy its own
goals.

27. It has tended to give less emphasis to the organization
and function of the nervous system that led to this
interaction.

28. A major contribution of this view is in describing the
individual as an active explorer of the environment.
An important part of intervention is helping the patient
explore the possibilities for achieving a functional task in
multiple ways.
The ability to develop multiple adaptive solutions to
accomplish a task and discover the best solution for
them, given the patients set of limitations.

29. Neurofacilitation approach including bobath, roods
approach, brunnstrom’sapproach, proprioceptive
neuromuscluarfacilitation (PNF) and the sensory
integration therapy, were based largely on assumptions
drawn from both the reflex and hierarchical theories of
motor control.
Neurofacilitation techniques focused on retraining motor
control through techniques designed to facilitate and /or
inhibit different movement patterns.

30. Examination of motor control should focus on identifying
the presence or absence of normal and abnormal
reflexes controlling movement.
Intervention should be directed at modifingthe reflexes
that control movement.

31. The importance for sensory input for stimulating normal
motor output suggests an intervention focus of modifing
the CNS through sensory stimulation.
A hierarchical theory suggests that one goal of therapy
is to regain independent control of movement by higher
centers of CNS.

32. These newer methods of are based on concepts
emerging from research in the field of motor control,
motor learning and rehabilitation science.
Clinical implication: a task oriented approach to
intervention assumes that patients learn by actively
attempting to solve the problems inherent in the
functional task rather than respectively practising
normal patterns of movement.