Kinesiology Lecture 19 Motor Control

Movement is not just

motion

movement is more realistically the process (or cycle) of _ and _

perception, action

Thirst, while 'internal', requires seeking water: _ from within and then _

perception, act

perception driven by _ specifying movement choices

environment

should DF

3

elbow DF

1

radioulnar DF

1

wrist DF

2

how many muscles about _ DOF

26

how many motor units about _ DOF

2600

any individually controllable unit of action

degrees of freedom (DOF)

When a DOF is lost, the command "Each do X" fails if every individual element (DOF) is

individually controlled

The ability to regulate or direct the mechanisms essential to movement

motor control

Emphasis on the _ of multiple systems in achieving control over the musculoskeletal elements to solve a motor problem or achieve a goal

interaction, motor control

theories of motor control include

reflex, hierarchical, systems

Sensory input drives (is required for) movement

reflex theory

reflex theory: Stimulus-response is mechanism for

movement

reflex theory: _ was the basic unit of movement

reflex

reflex theory: complex movement is a summation of

basic reflexes

Complex movements are a result of a chaining together of elemental reflexes

chain hypothesis

chain hypothesis is apart of which theory

reflex

Structural-functional relationship in CNS is

hierarchical

Since CNS has higher and lower "centers" then spinal cord is represented as a relay (spinal cord = reflex) between muscle and cortex (cortex = volition)

hierarchical theory

Movements are controlled not muscles in which theory

hierarchical

theory: how brain controls movement

hierarchical

reflex outside to in control

peripheral

hierarchical inside to out control

central

Peripheral (feedback) or Central (feedforward) control alone are incomplete in this

systems model

peripheral control also called

feedback

central control also called

feedforward

Not only do we need these two styles of control, but we also need to account for the role that task and environment play in the organization of movement.

systems model

the blacksmith study: Consistent task-level function: _ variability of hammer to anvil. • Variable _ kinematics (motions).

low, joint

• Interactive systems control behavior to achieve

task goals

reflex is the DOF theory

reflex

EMG pattern of a movement is the DOF theory

hierarchical

action / goal / image of achievement theory

systems

Notion of movement as _ (based on constraints from within (individual) and out (task and environment

emergent

DOF working together in order to achieve some task

synergies

Limits the ways in which a movement is executed without leading to uniqueness

constraints

_ is emergent

movement

Movement (pattern) emerges from the interaction of the

individual, task, environment

constraints individual include

Mobility • Force Generation • Muscle Tone • Endurance • Sensory Information • Selective Control • Adaptive Capacity • Speed • Pain • Coordination • Posture • Balance • Cognitive and Psychological

We call these individual constraints the

components of movement

_ Factors (structure-function of relevant subsystems for movement)

individual

Constraints: Task - Categorized by Organization

discrete (a brief task), serial, continuous

constraints task organization: Well defined beginning and end

discrete (a brief task)

constraints task organization: End point is an attribute of the task

discrete (a brief task)

constraints task organization: Multiple discrete movements linked together into a functional (usually) motor pattern

serial

constraints task organization: Order of tasks is usually important

serial

constraints task organization: Usually rhythmical in nature

continuous

constraints task organization: Has a beginning and an end but it has an extended execution stage

continuous

constraints task organization: End point may be an attribute of individual or task

continuous

Constraints: Task - Categorized by Predictability

open, closed

constraints task predictability: Task performed in a changing environment • Variability/flexibility

open

constraints task predictability: Task performed in a relatively fixed environment

closed

constraints task predictability: less task variability between trials

closed

Constraints: Environmental include

regulatory, non-regulatory features, affordances

constraints environmental: size, shape, and weight of a cup to be grasped

regulatory

constraints environmental: Color of cup doesn't matter. background noise / distractions.

non-regulatory

Affordances provided by the

environment

What the environment affords in terms of action

affordances

the _ includes the medium, the substances, the surfaces and their layouts, the objects, places, other persons and animals, and so on

environment

terrain is fixed and objects/ people are stationary

stationary

supporting surfaces, objects, or people are in motion (escalator, treadmill)

motion

Gentile's Taxonomy of Tasks: Classifying Activities: function of the action includes

body stability and body transport

Gentile's Taxonomy of Tasks: Classifying Activities: environmental context includes

stationary and motion

Gentile's Taxonomy of Tasks: Classifying Activities function of the action of body stability and body transport includes

no manipulation and manipulation

Gentile's Taxonomy of Tasks: Classifying Activities: environmental context of stationary and motion includes

no intertrial variability and intertrial variability

no intertrial variability means

closed

intertrial variability

open

least complex of Gentile's Taxonomy of Tasks: Classifying Activities

static erect posture sitting/std

most complex of Gentile's Taxonomy of Tasks: Classifying Activities

cross crowded street with cane

closed to open scale goes from

stationary no intertrial variability, stationary intertrial variability, in motion no intertrial variability, in motion intertrial variability

Set of processes associated with practice or experience leading to relatively permanent changes in the capacity to produce skilled action

motor learning

Process of acquiring capability for skilled action • Results from experience or practice • Cannot be directly measured • Permanent behavior changes

motor learning

Perform pre-post test at the end of one treatment session (pre-test) and the beginning of the next (before intervention-post-test)

motor learning

motor learning: What you see at the _ of the treatment session will most often reflect a _ of temporary performance changes (i.e., performance) and relatively permanent effects of your treatment intervention (i.e. learning)

end, combination

What you see on the post test in this case can be said to "reflect"

motor learning

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill)

cognitive stage, associative stage, autonomous stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Understand nature of task, develop strategies and determine how to evaluate task

cognitive stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Variable performance as person tries variety of strategies

cognitive stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Performance improvement is large

cognitive stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Strategy has been selected - refinement

associative stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Less variability but slower improvements in performance

associative stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Little skill required

autonomous stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Not much attention required

autonomous stage

Stages of Motor Learning: Fitts and Posner Three-Stage Model (three phases in learning a new skill): Can focus on other environmental factors that may impact execution of the skill

autonomous stage

Stages of Motor Learning: Systems ThreeStage Model

stage one novice, stage two advanced, stage three expert

Controlling and releasing DOF is basis for

learning skills

systems stages: Movement is simplified by "freezing out" some of the available DOF.

stage one novice

systems stage: Reinstatement and/or release of DOF. But controlling these DOFs reactively

stage two advanced

systems stage: Now the actor utilizes entirely the reactive phenomena which arise.

stage three expert

Practice and Feedback are the Cornerstones of

motor learning

Trial time > rest time • Fatigue issues

massed

Rest time >/= trial time

distributed

one task under same conditions

constant practice

one task under different conditions

variable practice

block (perform) tasks in sets of repetitions

block

switching among tasks during practice (during sets)

random

massed vs. _ practice

distributed