MOTOR CONTROL.pptx

THEORIES OF MOTOR
CONTROL
Simran Jethani MPTh-1st
Department of NeuroPhysiotherapy
DVVPF’s College of Physiotherapy, Ahmednagar
Date:-19-07-2023

Learning Objectives:
• Understand :-
1. Various Theories Of Motor Control
2. Clinical Application Of The Theories
• Discuss the relationship between theories of motor control
and the parallel development of clinical methods related to
neurologic rehabilitation
• Compare and contrast various Rehabilitation Approaches

CONTENTS:-
1. Introduction
2. Theories of control
3. Sensory Components of Motor Control
4. Neuro-Rehabilitation Approaches

Introduction
• Motor control is defined as the ability to regulate or direct the mechanisms
essential to movement.
• Physical and occupational therapists have been referred to as “applied motor
control physiologists” (Brooks, 1986).
• As they spend a considerable amount of time retraining patients who have motor
control problems producing functional movement disorders.
Shumway cook. Motor Control. Issues & theories 4th edition

Theories Of Motor Control
• A theory is a set of interconnected statements that describe
unobservable structures or processes and relate them to each other
and to observable events.
• Shumway cook. Motor Control. Issues & theories 4th edition
• Richard Magi , David Anderson. Motor Learnin and Control. Concepts and Applications. Tenth Edition

Theories
Reflex Theory
Hierarchial
Theory
Systems
Theory
Motor
Programming
Theory
Dynamic
Systems
Theory
Ecological
Theory

Reflex Theory- Sherrington 1906
• For Sherrington, reflexes were the building blocks of complex behavior.
• Complex behaviour could be explained through the combined action of
individual reflexes that were chained together
LIMITATIONS
Does not explain
1.Both voluntary & spontaneous activity.
2.Movement In absence of sensory stimulus
3. Movement too rapid to allow sensory feedback
4.Single stimulus resulting in varying responses
depending on context and descending commands.

Clinical Implication
• If chained reflexes are basis for function- Clinical strategies designed to test
reflexes should allow therapists to predict function.
• Patient’s movement behaviours would be interpreted in terms of the 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.

Hierarchical Theory- Hughlings Jackson 1997
• Organisational Control – Top down
• Each successively higher level exerts control
over the level below it.
LIMITATIONS
Cannot explain the dominance of reflex behavior in
certain situations in normal adults.
For Eg. Withdrawal from a hot surface.

Clinical Implication
• Abnormalities Of reflexes- Explain disorders in motor control
• Signe Brunnstrom - Influence of higher Centres temporarily or
permanently interfered with, normal reflexes become exaggerated
and so called pathological reflexes appear.
• Berta Bobath - The release of motor responses integrated at lower
levels from restraining influences of higher centers, especially that of
the cortex, leads to abnormal postural reflex activity

Motor Programming Theories- Bernstein, 1967; Keele, 1968; Wilson, 1961
• The concept of a central motor pattern, or motor program, is more flexible than the concept of a
reflex because it can either be activated by sensory stimuli or by central processes.
• The grasshopper or locust experiment- evidence
• Hierarchically organized motor programs.
LIMITATIONS
• Central motor program cannot be considered to
be the sole determinant of action
• Does not take into account that the nervous system must
deal with both musculoskeletal and environmental variables
in achieving movement control.

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

Systems Theory- Bernstein, 1967
• Bernstein, recognized that you cannot understand the 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.
• Whole body- a mechanical system, with mass, and subject to both external
forces such as gravity and internal forces such as both inertial and movement-
dependent forces.
• Many degrees of freedom that need to be controlled - hierarchical control
exists to simplify the control of the body’s multiple degrees of freedom.
• Higher levels > lower levels > synergies, or groups of muscles that are
constrained to act together as a unit.

Dynamic Systems Theory- Kamm Et Al., 1991; Kelso & Tuller, 1984; Kugler &
Turvey, 1987; Perry, 1998; Thelen Et Al., 1987
• Dynamic systems theory comes from the broader study of dynamics or synergetics within the physical
world.
• “self-organization” is a fundamental principle of dynamic systems.
• This principle states that when a system of individual parts comes together, its elements behave
collectively in an ordered way.
• This principle applied to motor control predicts that movement could emerge as a result of interacting
elements, without the need for specific commands or motor programs within the nervous system.
• Dynamic theory suggests that the new movement emerges because of 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.

• Little variability ~ repetative task~ prone to injury
• Much variability ~ impaired movement
Performance ~eg. Ataxia
• DST = Small variability ~ Highly stable behaviour ~
attractor state
• Attractor states may be considered highly stable,
preferred patterns of movement; many are used to accomplish common activities of daily
life.

Limitations
Presumption that the nervous system has a less important role in determining the animal’s
behavior, giving mathematical formulas and principles of body mechanics a more dominant
role in describing motor control.
Understanding the application and relevance of this type of analysis to clinical practice can
be very difficult.
When working with the patient who has a CNS deficit, 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.
Examination and intervention must focus not only on the impairments within individual
systems contributing to motor control, but also on the effect of interacting impairments
among multiple systems.

Ecological Theory – Gibson 1966
• The ability to use perceptions to guide action emerges early in life.
• Actions require perceptual information that is specific to a desired goal-
directed action performed within a specific environment.
• Gibson stressed that it was not sensation per se that was important to the
animal, but perception.
• Broadened the understanding of nervous system function from that of a
sensory/motor system, reacting to environmental variables, to that of a
perception/action system that actively explores the environment to satisfy
its own goals.

Limitations
• It has tended to give less emphasis to the organization and function of the nervous system
that led to this interaction.
• The research emphasis has shifted from the nervous system to the organism/environment
interface
• The active exploration of the task and the environment in which the task is performed allows
the individual to develop multiple ways to accomplish a task.
• Adaptability is important not only in the way we organize movements to accomplish a task,
but also in the way we use perception.
• The ability to develop multiple adaptive solutions to accomplishing a task requires
that the patient explore a range of possible ways to accomplish a task and discover
the best solution, given his or her set of limitations.

Sensory Components of Motor Control
• 3 important sensory aspects of motor control are :
Touch
• Movement accuracy
• Movement consistency
• Movement timing
• Movement force
adjustments
• Estimate movement
distance
Proprioception
• Feedback about limb
displacement- basis for
spatial position
• Feedback - limb
velocity & force, which
influence movement
distance accuracy.
Vision
• Monocular & Binocular
vision
• Central & peripheral
Vision
• The Coordination of
Vision and Movement

Neurologic Rehabilitation: Reflex-Based
Neurofacilitation Approaches:
• Various Approaches such as : Bobath approach, the Rood approach, Brunnstrom’s
approach, proprioceptive neuromuscular facilitation (PNF), and sensory
integration therapy
Based on the assumptions drawn from both reflex & hierarchical theories of motor
control

Task-oriented Approach:
• Assumed - normal movement emerges - interaction among different systems,-
each contributing different aspects of control
• Abnormal motor control suggest - movement problems - impairments within
one or more systems- controlling movement
• Mvt – organized towards behavioural goal
• Abnormal Mvt – is not only lesion but effort from remaining systems to
compensate for the loss and still functional.

Clinical Implication:
• Retraining movement- essential to work on functional tasks rather than movement
patterns for movement’s sake alone
• Patients learn - actively attempting to solve problems inherent in a functional task
rather than by repetitively practicing normal patterns of movement
• patients are helped to learn a variety of ways to solve the task goal rather than a
single muscle activation pattern.

Recent Advances
The effect of a task-specific locomotor training strategy on gait stability
in patients with cerebellar disease: a feasibility study
Seung-Jin Im et. al. Disability and Rehabilitation May 2016
• Nineteen patients with degenerative cerebellar ataxia were recruited to participate
in the study
• 12-week locomotor training program, two times per week for 1.5 h per session
• Outcome measures – 1.The patients disease severity was evaluated using the
International Cooperative Ataxia Rating Scale (ICARS)
2. stride-to-stride variability - walking stability and control.
3. Slow walking test- instability during gait

Intervention-
1. The training began with the transferring of
the center of the body weight safely in upright
standing.
2. Locomotor relearning training- In each
walking phase, their attention was directed to
the conscious perception and control of the
center of the body stability, trunk and limb
alignment, and stepping kinematics
Conclusion:
This study has provided preliminary evidence
that restorative rehabilitation strategies
targeting disease specific locomotion
symptoms may be helpful for reducing ataxic
gait and improving motor control during
walking in patients with cerebellar
dysfunction.

References :-
• Shumway cook. Motor Control. Issues & theories 4th edition
• Richard Magi , David Anderson. Motor Learnin and Control. Concepts and Applications.
Tenth Edition
• The effect of a task-specific locomotor training strategy on gait stability in patients with
cerebellar disease: a feasibility study, Disability and Rehabilitation, DOI:
10.1080/09638288.2016.1177124

MOTOR CONTROL.pptx

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