Motor Control and Motor Learning Flashcards
Motor Control
- Movement is a product of the contributions of many systems working together within their own maturational level to produce movement tailored for that particular individual at that particular time, within that unique environment, to perform a specific task.
Motor output from CNS produces “action” through the following mechanisms
- Body’s effector system
- Muscles and joints
- Degrees of freedom
Tasks grouped according to functional categories: (3)
- Bed mobility tasks
- Transfer tasks
- Walking and ADL’s
Tasks grouped according to critical attributes that regulate neural control mechanisms: (2)
- Discrete
- Beginning and end
- Continuous
- End point is not inherent characteristic of task
- e.g., running-ending decided by performer
Tasks grouped according to whether the base of support is stable or in motion: (2)
- Stability
- Stable base of support
- Sitting, standing
- Mobility
- Moving base of support
- Running, walking
Tasks grouped according to whether object manipulation is required
- Adding a manipulation component increases the demand for stability during task performance
Tasks grouped according to movement variability: (2)
- Open movements
- Performer adapts behavior within constantly changing environment
- Tennis, soccer
- Closed movements
- Stereotyped, fixed, predictable
Environmental Constraints on Movement: Regulatory
- Movement must conform to regulatory features for goal achievement
- These features shape the movement itself
- Size, shape, weight of object to pick up or surface on which to be stable
- 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
Environmental Constraints on Movement: Non-regulatory
- Movement does not have to conform to these features
- May or may not affect movement
- Examples: noise, lighting
THEORIES OF DEVELOPMENT
- Theories describe various patterns of behavior and why those behaviors occur
Theoretical Views (5)
- Neural-Maturationist
- Cognitive-Behavioral
- Cognitive-Developmental
- Motor Learning
- Dynamical Systems
Neural-Maturationist (theoretical view)
- Stages of motor development occur as a result of CNS maturation
- Organizational, top-down control, wherein higher levels exert an influence over lower levels
- These higher levels contain motor programs that store rules for generating movements.
- Appearance/disappearance of reflexes occurs with maturation of the CNS
***Neural-Maturationist Model attributes progressively Sophisticated movements to neurological maturation
Neural-Maturationist Theory Limitations (theoretic view)
- Presumes that reflexes still play a role in all movement/ Where do spontaneous/voluntary movements fit in?
- Doesn’t answer question of how novel movements occur
Neural Maturationist Theory Clinical Implications
- Function could be predicted by presence/absence of reflexes
- Pediatric PT developed based on this model: exam of reflex development and motor milestones dominate neurological testing
- clinical interventions based on increasing or decreasing reflex effects still used today
- Many current therapeutic exercise approaches have their basis in this model
Neural-Maturationist Summary
- Nervous system drives change
- Motor milestones in a predictable, sequential order over time
- What skills change and when
- Useful to tell us if a child is progressing in a typical fashion over time
But there is no How and Why of motor skill change
Cognitive Theories
- Focus is on the advancement of the development of thinking (motor skill interaction with other areas of development and the experience of acting on the world
Cognitive -Behavioral
- No identifiable stages
- Development occurs through interaction with the environment
- The building blocks are associated pairings in the environment (classical conditioning) and the behavioral consequences of reward and punishment (operant conditioning)
Cognitive -Developmental
- Development occurs as a result of sensory and motor interactions with environment at the different stages
- 4 stages of development with cognitive milestones
- first actions use reflexes and progress to voluntary actions
Cognitive theories limitations
- The interrelatedness of movement skill to cognition was not described
Cognitive theories clinical implications
- Therapist needs to provide a variety of sensory experiences to encourage the child to interact with the environment
- Use direct hand over hand if necessary to provide interaction with objects
Motor Learning theory
- Movement conditions, parameters of the motor program, outcome of the movement, and how the movement felt are stored in short-term memory until the following 2 schema can be extracted
-
Recall schema (motor components)
- Movement conditions
- Motor program parameters (trial and error practice
-
Recognition schema (sensory components)
- Knowledge of results
- Sensory feedback from movement
-
Recall schema (motor components)
Motor Learning from a temporal perspective in 3 stages
- Cognitive Stage - Early stage involves understanding the task, selecting a strategy, and constraining degrees of freedom to make the task easier. Characterized by large number of errors, but important to let patient be an active participant.
- Associative Stage - Intermediate stage allows task refinement, allowing more degrees of freedom with less muscle co-contraction, increasing coordination and decreasing variability of performance
- Autonomous Stage – Final stage wherein speed and efficiency of performance improves and automatic skills emerge. Patients ready for advanced challenges via distraction or new combinations of skills
***Learning is the ongoing process of updating the recognition and recall schema with each movement that is made (during each of the 3 stages):
Repetition Important!
Dynamical Systems Theory
- All systems will demonstrate a change over time, & thus are dynamic
- Self-organization of the interaction of systems is the main dynamical action principle
- Collection of individual parts come together as a unit without commands from a higher center
- Non-linear behavioral change occurs in response to a single control parameter of that behavior
- New movements emerge because of readiness within the system
Dynamic Systems Theory- Limitations
- De-emphasized neural contributions at both individual and environment levels
Dynamic Systems Theory- Clinical implications
Which theory is the best???
- One that incorporates best concepts of all previous theories
AND
- One that leaves room for growth as new evidence identifies new insights into motor control
What is Motor Learning?
-
Acquisition or modification of movement in normal subjects that is relatively permanent
- Result of practice or experience
- Recovery of function: reacquisition of movement skills lost through injury/illness
Relating Motor Training vs. Performance vs. Learning
- Training – performer provided with solutions to problems
- Performance – temporary change in behavior observed during practice
- Learning – permanent change in behavior based on the learner’s ability to actively problem solve and derive the solution in a variety of circumstances
Stages of Motor Learning/Patient Progress – 2 distinct phases
-
Acquisition or practice phase (1)
- Initial fumbling attempts
- Skills are learned or relearned
- Indicates performance
-
Retention & Transfer phase (2)
- Mastery of a skill
- Information stored for retrieval and application to novel situations
- Indicates learning
Is training or learning more important in therapy session?
- Training is necessary if a client doesn’t know the performance parameters of a task (e.g., walking with crutches)
- But emphasis on Learning is essential to allow client to function without your constant input (e.g. managing obstacles in their environment that were not specifically practiced)
***Only individuals who are involved in their learning are willing
to make the effort to change their behaviors accordingly
Practive levels
-
Practice is the continuing and repetitive effort to become proficient in a skill
- Practice should be accurate, since faulty practice may lead to development of bad habits and inefficient postures
- Practice should be active, not passive, and initiated by the patient
- Practice should incorporate enough variability to allow the patient to explore the perceptual motor workspace and to discover solution to movement dilemmas
- Practice should be task specific
Practice conditions- Transfer
Transfer: amount of transfer is dependent on similarity between two tasks/environments so that the neural processing would be similar {random and variability in practice= greater transfer}
Practice conditions- Mental Practice
Mental Practice: enhances skill acquisition-stimulates brain {visualizing motor skill creates electrical activity in the nerves and muscles involved in performing skill}
Practice conditions- Guidance vs Discovery
Feedback
-
Feedback – refers to the use of sensory information for the control of action in the process of skill acquisition. It’s a powerful variable affecting learning.
- Provides guidance, a reference for correction, and motivation
- Types of feedback
- Intrinsic feedback
- Extrinsic feedback
Intrinsic feedback
-
Intrinsic feedback
- Comes from within one’s body via sensory systems, perception (closed loop)
- Intrinsic feedback may be distorted in patients with neurological lesions
Extrinsic feedback
-
Extrinsic feedback
- Is augmented information provided from an external source
- Purpose is to provide person with Knowledge of Results (outcome of movement) or Knowledge of Performance (how they did with each stage of movement)
Plasticity occurs under 3 conditions
- Normal brain development when immature brain begins to process sensory information through adulthood
- Learning events
- Brain injury-to compensate for lost functions or to maximize remaining functions
***Intensive rehabilitation if we did not develop normally and/or injury/disease process caused LOF
