KIN 3513 topic 5

Motor control theories

motor control theory

describes and explains how the nervous system produces coordinated movement to successfully perform a variety of motor skills in a variety of environments

coordination

the relationship of head, body, and limb movements at a specific point in time relative to the patterning of environmental objects and events during a skill performance

degree of freedom (df)

number of independent components in a control system and the number of ways each component can vary; depends on the level of control

open loop system

doesn’t use feedback; executive provides all the info for effectors to carry out movement

closed loop system

uses feedback; executive issues info to effectors sufficient to initiate movement; relies on feedback to continue and terminate movement

closed loop sequence

executive system → effector → comparator → error signal

closed loop system example

balancing on one leg

open loop sequence

executive system → effector

open loop system example

witching on a light switcfh

motor program-based theory

memory-based construct that controls coordinated movement

dynamical systems theory

the control of coordinated movement by emphasizing the role of environmental info and dynamic propertiesof the body and limbs

motor program

decision-making stages determine what program to initiate and have some role in the eventual form of movement

conceptual model of motor program theory

open loop control of actions provides the organization or pattern that the feedback process can modify later if necessary

schema

a rule or set of rules that serves to provide the basis for a decision

GMP

control mechanism responsible for controlling the movement coordination patterns of classes of actions

motor response schema

responsible for providing the specific rules governing the performance of a skill in a given situation

3 subsystems of dynamical systems theory

task constraint, environmental constraint, individual constraint (effector)

muscle synergies

groups of muscles (and joints) constrained to act as functional units by the nervous system to act cooperatively to produce an action

perception-action coupling

inextricable linkage between info specifying body, environment, and action control; preception is the detection and utilization of critical info for control of action

affordances

the reciprocal fit between characteristics of the person and the environment that allow certain actions to happen (ex: the ratio of leg length to stair height determines whether a set of stairs is climbable

present state of control theory

both motor program-based theory and dynamical systems theory dominate and research using both approaches has shown that theory of motor control cannot focus exclusively on movement info specified by the CNS