Theories of Motor Control Lecture Slides, Slides of Engineering Physics

Download Theories of Motor Control Lecture Slides and more Slides Engineering Physics in PDF only on Docsity!

Chapter 4

CHAPTER 4

MOTOR CONTROL THEORIES

Chapter 4

THIS CHAPTER’SCONCEPT Theories about how we controlcoordinated movement differ in termsof the roles of central andenvironmental features of a controlsystem

Chapter 4

THEORY &PROFESSIONALPRACTICE „^ Theory helps understandphenomena „^ Theory explains the reasons whyphenomena exist or behave „^ Motor control theory provides onea base that leads to effective skillinstruction and practiceenvironments

Chapter 4

DEGREES OFFREEDOM PROBLEM „^ How does the nervous systemcontrol a given pattern? „^ Reflects the number ofindependent components of thesystem( e.g. controlling ahelicopter) „^ Motor control theory account forhow the nervous system solves thedegrees of freedom problem

Chapter 4

Application „^ When we first learn or relearn amotor skill, all performers operatein a closed loop fashion.^ ‹^

Need for feedback ‹ Need for instruction „^ As we become better at the motorskill we switch to more open loopcontrol.^ ‹^

Effective practice

Chapter 4

Two Theories of Motor Control^ „^ Motor program theory^ ‹

Instruction are specified by the CNS ‹ Control process is managed by a motor program ‹ Motor program organizes, initiates, and carries outintended actions „ Dynamic System Theory ‹ Instructions are influenced by environment andinteraction of the body, limb, and nervous system

Chapter 4

GENERALIZED MOTORPROGRAM^ „^ Proposed by Schmidt accounts for adaptiveand flexibility of coordinated-movementbehavior^ „^ Represents a patter of movement (class ofactions) that can be modified to yieldvarious response outcomes^ ‹

Some elements of GNP are fixed from trial totrail (invariant) ‹ Some elements of GNP are flexible(parameters)

Chapter 4

Fixed Vs. Flexible Features ON a blank sheet of lined paper write yourname according to the following instructions:^ 1.^

With your dominant hand 2. With your non-dominant hand 3. Holding the pen/pencil in your mouth 4. Holding the pen/pencil in your toes

Chapter 4

INVARIANT FEATURES (Fixed)^ „^ Regardless of how your wrote your name severalunderlining features of your signature remainedconstant.^ „^ Fixed features are similar to fingerprints (can identifyeach of us)^ „^ Three Common Invariant Features

1.^

Relative timing

2.^

Relative force used

3.^

Sequence of actions or components

Chapter 4

Invariant features (continued) Regardless of the constraints, you spell your namethe same way every time. If you name is Spike, the “p” always follow the S.Regardless where the ball is set, the approach,jump, arm swing, and ball contact must besequentially executed.^ The^

sequence of action

or order of the

components is an invariant characteristic.

Chapter 4

Swimming example^ „^ Arm movement in freestyle stroke consists of 5components.^ ‹

35% is accounted by the entry ‹ 13% is accounted by the catch ‹ 08% is accounted by the mid-pull ‹ 12% is accounted by the finish ‹ 32% is accounted by the recovery „ These percentages remain the same regardless of thefrequency in relative timing and force

Chapter 4

PARAMETERS

„^ Defines how to execute the program „^ Changes from situation to situation „^ Changes from one trial to another „^ Includes

1.^

Time can increase or decrease (overall duration)^ 2.

The size of the movement can increase or decrease (overall force)^ 3.

Specification of Muscles & Limbs used

Chapter 4

The schema connection „^ A short stop is able to throw to different basesfrom various positions on the file by assigningappropriate parameters values to the motorprogram. „^ But how does the performer know exactly howmuch force or how fast the ball should bethrown?

Chapter 4

Schema Connection (continued) „^ The answer lies in the development of aschema which is Schmidt’s second aspect ofmotor program theory. „^ Schema is rule or relationship that directsdecisions making when a learner is faced with amovement problem.