motor control & motor learning Flashcards
motor control
is defined as the ability to regulate or direct the
mechanisms essential to movement.
motor control is information processing..
related to activities carried out by
the central nervous system that organize the musculoskeletal system to
create coordinated, goal-directed movements.
two control strategies:
- Feed-forward strategy
- Feed-back strategy
The field of Motor Control is directed at studying the:
nature of movement and how movement is
controlled
Movement emerges from the interaction of three factors:
- Individual (I)
- Task (T)
- Environment (E)
Individual Action: Constraints on Movement
- ways a movement can be carried out
The body is characterized by a high number of muscles
and joints, all of which must be controlled during the
execution of coordinated, functional movement
* Redundancy of human systems
* Degrees of freedom problem: choosing among
equivalent solutions and then coordinating the many
muscles and joints involved in a movement
Individual Perception: Constraints on Movement
- what does this provide information about?
Integration of sensory impressions into
psychologically meaningful information
- state of the body and
features within the environment critical to
the regulation of movement
Individual Perception: Constraints on Movement
- what does this involve to add interpretation and meaning to afferent information?
Involves both peripheral sensory
mechanisms and higher-level processing
Cognition Individual: Constraints on Movement
- what do cognitive processes involve?
include attention, planning,
problem solving, motivation, and emotional
aspects of motor control that underlie the
establishment of intent or goals
Task: Constraints on Movement
- what are the classifications of functional categories?
- nature of the task being performed in part determines the type
of movement needed, so several classification parameters
developed - Bed mobility tasks
- Transfer tasks
- Walking and ADLs
Task: Constraints on Movement
what are the attributes that regulate neural control mechanisms
- discrete
- continuous
- discrete classifications:
- Definite beginning and end
continuous classification
- No recognizable beginning and end points
- End point is not an inherent characteristic of task
- Example: walking, running, swimming
classifications: base of support
- stability & ex:
- mobility & ex:
- stability & ex:stable base of support (e.g. sitting or standing)
- mobility & ex: moving base of support (e.g. walking or running)
classification: whether object manipulation is required
sequenced task – increase the demand for stability (e.g. standing & lifting)
classification: movement variability
- open movements - constantly changing or unpredictable environments
- closed movements – relatively fixed, predictable environments
Regulatory Environment Constraint on Movements
- Movement must conform to regulatory features in order to achieve to the goal of the
task - These features shape the movement itself
- Examples: differently-sized cups require different grasping patterns; walking on an
uneven grassy surface impacts the gait pattern differently than walking on a smooth
floor
non regulatory vs. regulatory
- Regulatory - movement must conform to regulatory features
*Non-Regulatory- movement does not have to conform to these features
* May or may not affect movement
* Examples: background noise, lighting
systems theory
describes the body as a mechanical system with many degrees of freedom
that need to control
define synergies
- what controls synergies
a group of muscles constrained to
act together as a unit to the solve degree of freedom problem
- higher levels of nervous system activate lower levels, which activate synergies
movements emerge from what 3 factors?
from the interplay between the body
system, external force, and variations in the initial condition
dynamic systems theory
comes from the broader study of dynamics or synergetics within the physical world
self-organization
states that when a system of
individual parts comes together, its elements behave collectively in an
ordered way – no need for a “higher” center issuing commands in order to achieve coordinated action
control parameter
ex?
a variable that regulates changes in the behavior of the entire system
ex: velocity
Variability of motor control in Dynamic Systems Theory
Variability is not considered to be the result of error, but rather as a necessary
condition of optimal function
theoretical framework -
basis for clinical methods
related to examination and intervention in patients
optimal variability:
too little outcome:
too much outcome:
small amount outcome:
- Optimal variability provides for flexible, adaptive strategies and allows for adjustment to environmental changes
- Too little variability can lead to injury (i.e. repetitive muscle strain)
- Too much variability can lead to impaired movement performance (i.e. ataxia)
- A small amount of variability indicates a highly stable behavior or a preferred pattern, viewed as attractor state
early definition
study of the acquisition and /or modification of movement
four concepts of motor learning
- Learning is a process of acquiring the capability for skilled action
- Learning results from experience or practice
- Learning cannot be measured directly, referred from behavioral changes
- Learning produces relatively permanent changes in behavior
performance
temporary change in motor behavior observed during practice
learning
relatively permanent change in behavior and involved in skill retention
closed loop: motor learning
control achieved by feedback
such that the actual response conforms to the desired response (or set point) by means of correcting any difference between them.
open loop: motor learning
the execution of preprogrammed movements, called a motor program, without perceptual feedback.
“muscle memory”
ex: gymnasts practice routine so much for years, until they can do it seeming “effortlessly”
Fitts and Posner 3 stage model
what are the three stages?
- cognitive stage
- associative stage
- autonomous stage
what is the cognitive stage?
Fitts and Posner 3 stage model
what is it that must be done
- try to understand the task and select a strategy for optimal performance
- has large # of errors and high degree of cognitive activity
- improvements are large :)
what is the associative stage?
Fitts and Posner 3 stage model
how should it be done?
- the best strategy has been selected
- begins the refine of skill
- small improvement in skill, small variability in performance
- autonomous stage
Fitts and Posner 3 stage model
* what presents success *
perform skill automatically with low level of attention
- ready for advanced challenges
systems 3 stage model’s emphasis is?
- what are the stages
emphasis on learning to control degrees of freedom of the body segments
- novice stage
- advanced stage
- expert stage
- novice stage
systems three-stage model
freeze degree of freedom
-learner simplifies movement by stiffening body segments to control degree of freedom.
- accurate performance of task but inefficient
- advanced stage
systems 3 stage model
release additional of degree of freedom
- biomechanical constraints o
