The discipline of Motor Control is the study of human movement and the systems that control it under normal and pathological conditions. Depends upon - Environmental result of the movement (Outcome) Movement pattern Neuromotor processes underlying movement

1. Theories of motor
controlDr. Maheshwari Harishchandre
Assistant Professor
M.P.Th (Neurosciences)
DVVPF College of Physiotherapy, Ahmednagar

2. Objectives
 What is motor control.
 Different theories of motor control
 Clinical implications.
 Limitations.

3. Motor Control
 Defn – The ability of regulate or direct the
mechanisms essential to movement.
 Why is it necessary to know?
 Movement emerges from three factors -

5.  Individual – Action, Perception, Cognition
 Task – Stability, Mobility, Manipulation
 Environment – Regulatory, Nonregulatory

6. Description
 The discipline of Motor Control is the study of human
movement and the systems that control it under
normal and pathological conditions.
 Depends upon -
 Environmental result of the movement (Outcome)
 Movement pattern
 Neuromotor processes underlying movement

7.  A theory of motor control is a group of
abstract ideas about the control of
movement.
 A theory is a set interconnected
statements that describe unobservable
structures or processes & relate them to
each other & to observable events.

8. Theories of Motor control
 Reflex theory
 Hierarchical theory
 Complex systems theory
 Motor Programming Theories
 Systems Theory.
 Ecological Theory

9. Reflex Theory
 Reflex Theory (Charles Sherrington)
 Complex behavior (movement) is
controlled by a series of chained
reflexes

11. • Sir Charles Sherrington, the integrativeSir Charles Sherrington, the integrative
action of the nervous system (1906)action of the nervous system (1906)
• This is based on the observation thatThis is based on the observation that
monkeys were unable to lift their arm aftermonkeys were unable to lift their arm after
resection ofresection of one sideone side of dorsal rootof dorsal root
ganglia.ganglia.  Therefore, sensory inputs mustTherefore, sensory inputs must
be essential in initiating movements.be essential in initiating movements.

12. Clinical Implications
 If the chained or compounded reflexes are
the basis of functional movement, clinical
strategies designed to test the reflexes
should allow the therapist to predict
functions.
 Patients movement behaviors would be
interpreted in terms of presence or

13. Limitations of Reflex TheoryLimitations of Reflex Theory
• Unable to explainUnable to explain
– Spontaneous and voluntary movementsSpontaneous and voluntary movements
– Movement can occur without a sensoryMovement can occur without a sensory
stimulus ex- Fast sequentialstimulus ex- Fast sequential
movements, e.g. typingmovements, e.g. typing
– A single stimulus can trigger variousA single stimulus can trigger various
responses (reflexes can be modulated)responses (reflexes can be modulated)

14. Hierarchical Theory
 Hierarchical Theory
(H Jackson 1930s)
 Movement is
controlled by a
system consisting of
3 levels with a rigid
top down
organization
 Higher centers
control lower
centers

15. • Higher centers are always control lowerHigher centers are always control lower
centerscenters
• Higher centers inhibit the reflexesHigher centers inhibit the reflexes
controlled by lower centerscontrolled by lower centers
• Reflexes controlled by lower centers areReflexes controlled by lower centers are
present only when higher centers arepresent only when higher centers are
damageddamaged

16. This theory suggest that motor controlThis theory suggest that motor control
emerges from reflexes that are nestedemerges from reflexes that are nested
within hierarchically organized levels ofwithin hierarchically organized levels of
the CNS.the CNS.
– A child’s capacity to sit, stand, and walkA child’s capacity to sit, stand, and walk
is related to the progressive emergenceis related to the progressive emergence
and disappearance of reflexesand disappearance of reflexes
– Brain stem reflexes (associated withBrain stem reflexes (associated with
head control) emerge before midbrainhead control) emerge before midbrain
reflexes (associated with trunk control)reflexes (associated with trunk control)

17. Hierarchical TheoryHierarchical Theory

18. Current Concepts Related toCurrent Concepts Related to
Hierarchical TheoryHierarchical Theory
 Each level of the motor system can actEach level of the motor system can act
on other levelson other levels
 Reflexes are not considered the soulReflexes are not considered the soul
determinant of motor control but only asdeterminant of motor control but only as
one of many processes important to theone of many processes important to the
generation and control of movement.generation and control of movement.

19. Clinical Implications ofClinical Implications of
Hierarchical TheoryHierarchical Theory
““When the influence of higher centers is temporarily orWhen the influence of higher centers is temporarily or
permanently interfered with, normal reflexes becomepermanently interfered with, normal reflexes become
exaggerated and so called pathological reflexesexaggerated and so called pathological reflexes
appear” Brunnstrom,appear” Brunnstrom,
““The release of motor responses integrated at lowerThe release of motor responses integrated at lower
levels from restraining, influences of higher center,levels from restraining, influences of higher center,
especially that of the cortex, leads to abnormal posturalespecially that of the cortex, leads to abnormal postural
reflex activity”…Bobath, 1965reflex activity”…Bobath, 1965

20. Limitations of HierarchicalLimitations of Hierarchical
TheoryTheory
• Environment and other non-CNS factorsEnvironment and other non-CNS factors
can affect movement, e.g. Thelen’scan affect movement, e.g. Thelen’s
experiments showed that baby’s steppingexperiments showed that baby’s stepping
response re-emerges with body weightresponse re-emerges with body weight
supportsupport
• Normal adults exhibit lower level reflexes,Normal adults exhibit lower level reflexes,
e.g. flexor withdrawale.g. flexor withdrawal

21. – Many studies found that movement isMany studies found that movement is
possible evenpossible even in the absence of stimuliin the absence of stimuli
or sensory inputor sensory input
– Sensory inputs are not required toSensory inputs are not required to
produce a movement but they areproduce a movement but they are
important inimportant in adapting and modulatingadapting and modulating
the movementthe movement
Motor Programming TheoriesMotor Programming Theories

22. Motor Programming TheoriesMotor Programming Theories
• Motor programs areMotor programs are
– Hardwired and stereotyped neural connections suchHardwired and stereotyped neural connections such
as central pattern generators (CPGs)as central pattern generators (CPGs)
– Abstract rules for generating movements at the higherAbstract rules for generating movements at the higher
levellevel
• Motor program can be activated by sensory stimuli or byMotor program can be activated by sensory stimuli or by
central processescentral processes

23. Clinical Implications ofClinical Implications of
Motor Programming TheoriesMotor Programming Theories
• Movement problems are caused by abnormalMovement problems are caused by abnormal
CPGs or higher level motor programsCPGs or higher level motor programs
• It is important to help patients relearn theIt is important to help patients relearn the
correct rules for actioncorrect rules for action
• Focus onFocus on retraining movements that areretraining movements that are
critical to a functional taskcritical to a functional task, not just specific, not just specific

24. Limitations of MotorLimitations of Motor
Programming TheoriesProgramming Theories
• Does not consider that the nervous system must dealDoes not consider that the nervous system must deal
with both musculoskeletal and environmentalwith both musculoskeletal and environmental
variables to produce movementsvariables to produce movements
– e.g. identical neural commands to elbow flexorse.g. identical neural commands to elbow flexors
can produce different movements depending oncan produce different movements depending on
the initial position of the arm and the force ofthe initial position of the arm and the force of
gravitygravity

25. Systems Theory:Systems Theory:
• How does the CNS select a solution from anHow does the CNS select a solution from an
infinite number of possibilities for a task?infinite number of possibilities for a task?
• SolutionSolution
– Higher levels activate lower levels whileHigher levels activate lower levels while
lower levels activatelower levels activate synergiessynergies, i.e. groups of, i.e. groups of
muscles that are constrained to act togethermuscles that are constrained to act together
as a unitas a unit

26. • Viewed body as a mechanical system,Viewed body as a mechanical system,
involving the interaction between mass,involving the interaction between mass,
external force (e.g. gravity), internal forceexternal force (e.g. gravity), internal force
• ““CoordinationCoordination of movement is the processof movement is the process
of mastering the redundant degrees ofof mastering the redundant degrees of
freedom of the moving organism”freedom of the moving organism”
(Bernstein, 1967)(Bernstein, 1967)

27. Systems Theory: Latash’sSystems Theory: Latash’s
Principle of AbundancePrinciple of Abundance
• SynergySynergy is ais a task-specifictask-specific covariation ofcovariation of elementalelemental
variablevariables with the purpose tos with the purpose to stabilize astabilize a
performanceperformance variable, i.e. minimize errors of avariable, i.e. minimize errors of a
performance variableperformance variable
– Reaching: joint rotation angleReaching: joint rotation angle stabilize handstabilize hand
positionposition
– Grasping: individual finger forceGrasping: individual finger force stabilize totalstabilize total
grasp forcegrasp force
– Standing stability: postural muscle activationStanding stability: postural muscle activation 
stabilize COPstabilize COP

28. Clinical Implications of SystemsClinical Implications of Systems
TheoryTheory
• Body is a mechanical system. ConsiderBody is a mechanical system. Consider
musculoskeletal factors underlying a patient’smusculoskeletal factors underlying a patient’s
movement problemmovement problem
• Changes in movements may not necessarily resultChanges in movements may not necessarily result
from neural changes, e.g. faster vs. slow gait, speedfrom neural changes, e.g. faster vs. slow gait, speed
during sit to standduring sit to stand
• Encourage the patient to explore variableEncourage the patient to explore variable

29. Dynamic Systems Theory:Dynamic Systems Theory:
Principle of Self-OrganizationPrinciple of Self-Organization
• Movement emerges as a result of interactingMovement emerges as a result of interacting
elements. No needs for specific neuralelements. No needs for specific neural
commands or motor programs.commands or motor programs.
• Variability of movement is normal. OptimalVariability of movement is normal. Optimal
amount of variability allows for flexible, adaptiveamount of variability allows for flexible, adaptive
strategies to meet the environmental demandstrategies to meet the environmental demand

30. Clinical Implications
 This theory helps in understanding the
physical and dynamic properties of human
body , we can make use of these
properties in helping the patients to regain
motor control

31. Limitation of Systems TheoryLimitation of Systems Theory
• Nervous system is fairly unimportantNervous system is fairly unimportant

32. Ecological Theory:Ecological Theory:
• Action is specific to the task goal and theAction is specific to the task goal and the
environmentenvironment
• Perceptual information of thePerceptual information of the
environmental factors relevant to the taskenvironmental factors relevant to the task
goal is necessary to guide the actiongoal is necessary to guide the action
• Limitations:Limitations:
– ↓↓ emphasis on nervous systememphasis on nervous system

33. Clinical Implications ofClinical Implications of
Ecological TheoryEcological Theory
• Individual is an active explorer of theIndividual is an active explorer of the
environment for learningenvironment for learning
• Individual discovers multiple ways to solveIndividual discovers multiple ways to solve
movement problems in environmentmovement problems in environment
• Fundamental to the play-based therapy forFundamental to the play-based therapy for
pediatric patientspediatric patients