Motor Control and Motor Learning - Comprehensive Notes

Motor Control

Motor control and motor learning are distinct fields of research.
They are relevant to physiotherapy because the ability to perform movement-based skills is a key aspect of human experience.
Motor control and motor learning are relevant to any human movement-related profession and psychology due to cognitive and motivational elements.
Motor control is the complex process involving the nervous system and musculoskeletal system that makes movement possible.
It involves processes related to activating, coordinating, and regulating the production of quality functional movement.
It relates to how the motor system is organized structurally and functionally.
It explains how it produces and executes movement to allow interaction with external objects and the environment.
Understanding how human motor control works helps in selecting appropriate interventions at impairment, activity, and participation levels.
Motor control is about how we execute or complete the movement at any one moment and how we turn our thoughts into action.

Theories of Motor Control

Six theories are mentioned in the textbook, but there are others.
Each theory provides an interpretation of how movement is generated.
They place different levels of significance on various neural structures and mechanisms involved in motor control.
Reflex Theory: A series of reflex responses to a stimulus combine to form the basis for functional movement.
Hierarchical Theories: Motor control is organized in a top-down structure with higher cortical association areas exerting control over other cortical regions, followed by the spinal cord level.
Motor Programming Theories: Movement is produced by central motor patterns, pre-programmed commands accessed and utilized for particular movements.
Systems Theories: Movement is produced by the synergistic interaction of multiple systems influenced by internal and external factors.
- The person, environment, and task play a role, and multiple systems evaluate information to produce the movement outcome.
Dynamic Action Theories: Movement results from the interaction between components of the motor system without specific commands or motor programs.
Ecological Theories: Detecting information in the environment relevant to the movement guides actions.
Current Theories: Movement results from multiple systems working in synchronicity, incorporating components of each theory.
Limitations: Each theory cannot be all-encompassing or totally correct as it cannot explain all components of movement.

Motor Cortex and Motor Control

Motor cortex (M1) is primarily responsible for the execution of motor commands.
Motor cortical areas are somatotopically organized (face, arm, leg) with broad overlapping areas.
Face and hands have a disproportionately large representation due to the need for precision and control.
The motor cortex represents a map of movements or spatial locations to which movements are directed rather than the control of individual muscles. *Goal-directed voluntary movements are achieved through three phases:
- Planning
- Initiation
- Execution
Planning the movement involves:
- Selecting an appropriate response to the current situation
- Planning the movement in physical terms, defining the sequence of muscle contractions
- Decision-making in the cortex and access to memory

This primarily occurs in the prefrontal cortex and posterior parietal cortex.

Initiating the movement involves:
- Pre-motor and supplementary motor areas where motor commands are devised and maintained until needed.
- Basal ganglia to refine the movement and prevent unsuitable movements.
Execution of Movement involves
- Motor neurons are activated, triggering the observable mechanics of the movement.
  - The motor cortex sends signals down the descending tracks through the spinal cord and through the skeletal muscle.
  - These are thought to comprise of hierarchical and parallel circuits.
  - Redundancy: The process of having multiple circuits that can achieve the same outcome. Multiple ways to move the body to achieve the same movement outcome.
    - Important for multitasking and complex sequential movements.
    - Useful for recovery of function after neural injury.
  - Higher levels control decision-making aspects and strategies for movement (association area and basal ganglia).
  - Lower level areas control the motor execution (brain stem and spinal cord).
  - Sensory Feedback: Movement is detected by sensory receptors in muscles and joints.
    - Proprioceptive feedback is processed hierarchically and integrated with other sensory sources like vision.
    - At the lowest level, sensory feedback forms spinal reflex loops.
    - At higher levels, sensory feedback is integrated in the somatosensory cortex via the thalamus and transmitted to the cerebellum.
  - Cerebellum: A copy of the descending motor command is transmitted from the cortex to the cerebellum (efference copy).
    - The cerebellum compares the efference copy to the sensory input (intended vs. actual movement) and returns this information to the cortex.
    - Adjusts the motor output to reduce movement errors.
  - Basal Ganglia:
    - The corticobasal ganglia thalamo cortical loop.

Motor Learning

Compared to motor control, motor learning relates to the acquisition and or modification of skilled action or task completion.
It's about learning to move better, more efficiently, more effectively, or in a more skilled way.
Motor learning is considered a set of processes associated with practice or experience that leads to a more permanent change in capability for producing a skilled action.
Learning is a process of acquiring capability for skilled action.
Learning results from experience or practice.
Learning cannot be measured directly; it is inferred by a change in behavior, improved performance, or outcome.
Learning produces permanent changes.
Motor learning involves new strategies for sensing information and involves perception, cognition, and action processes.
Motor learning processes include the interaction of an individual with both the task and the environment to find a solution to the movement.
The essence of motor learning is about producing more effective movements attained through practice.
The focus on movement of the body is what distinguishes motor learning from perceptual or purely cognitive thought-based learning.
Krakauer et al. (2019) Definition: Provides 2 parts. Skill acquisition, and skill maintenance.
- Skill acquisition: the process by which an individual acquires the ability to rapidly identify an appropriate movement goal given a particular task context, select the correct action given a sensory stimulus
- Skill maintenance: the ability to maintain that performance level under changing conditions over time.

What Motor Learning is NOT:

A purely learned cognitive process
- e.g., strategy and tactics in sports
The same as performance
- Motor performance is an observable attempt of an individual to produce a voluntary action susceptible to temporary factors.
- Motor learning is a relatively permanent change in internal processes that determine an individual's capability of producing a motor task.
*Improved Performance
*Reduced Errors
*Increased Consistency
Motor learning is essential to all physiotherapists as we focus on patients learning or relearning everyday motor skills.
Being skilled in any motor task requires effective goal selection, action selection, and accurate and precise action execution.
Improvements at any stage of this pathway of goal selection, action selection, and action execution can be described as part of motor learning.
Besides improving skill, motor learning also encompasses mechanisms for maintaining consistent performance in a fluctuating environment.
Adapting to ongoing changes to maintain a previously attained level of performance is also an important aspect of motor learning like different surfaces, if it's windy or rainy, if walking outdoors or walking in a crowded versus open space, up and down slopes, steps or stairs for example.
Motor Adaptation: A particular type of behavioral change that involves adjusting how an already well-practiced action is executed to maintain performance in response to a change in the environment or the body.
- either by selecting an alternative well-practiced action
- or modifying how the current action is executed.
*The goal of the action remains the same.
*Recalibration of actions due to dynamics of the environment or the body itself changing.

Error Correction

The system learns through error over multiple trials, making small adjustments each time.
*Task Error
*Implicit Adaptation
*Explicit Compensation
* Explicit compensation seems to be driven by overall task error.
Numerous regions throughout the brain have been identified as contributing to motor learning.
Learning changes the structure and function of the brain through neuroplasticity.
- Reorganization of the structure or function of the nervous system through responding to intrinsic and extrinsic stimuli.
- Adaptive: Improvements in outcomes not related to compensation.
- Maladaptive: Negative outcomes such as what happens in persistent pain.
- Neuroplasticity is use-dependent and specific.
- Repetition and intensity matter for neuroplasticity to occur.
- Neuroplasticity is improved by sensory, cognitive, motor, and social stimulation. *Priming: Doing an activity to prepare or prime the brain to be in a state of being more ready for the next task and this is known to increase neuroplasticity.
  - Motor imagery, mental practice, sensory priming, movement-based priming, stimulation-based therapy, or pharmacology.

Memory

Memory: The storage of material that results from activities of information processing.
Involves a process of storing, reattaining information that was stored, and then using that information.
*Hippocampus
*Frontal Lobes
- Primary and supplementary motor areas for motor memories.
Memory can be divided into:
- Sensory
  - brief storage of sounds, sights, or other senses.
- Short Term
  - Lasts between 15 and 30 seconds with a capacity limit of about seven plus or minus two items.
- Long Term
  *Limitless capacity and is long lasting.
  * Explicit memory or declarative
  *Facts, events, and personal experiences
  *Implied memory
  *Procedures and abilities that are the motor skills learned through practice.
Coding is the process to get information from short term memory to long term memory where it is stored
Decoding is taking information back out of memory and reusing it, which is also considered retrieval.
Attention is important since what we pay attention to is what goes into memory because we must first consciously see, hear, or experience it in the first instance.
Forgetting can occur when we don't pay attention, fail to consolidate information, decay through degeneration or interference, motivated or painful forgetting, or a retrieval failure.

How We Learn

*Implicit OR Non Declarative Learning
*More Reflexive
*Automatic
*Known Habitual in Nature
*DOES NOT require Higher Cognition
*Rather Requires Frequent Repetition

Implicit or non-declarative learning is then broken down into non-associative, associative, and procedural learning.
*Non-Associative Learning
*Habituation
*Sensitization
*Associative Learning
*Classical Conditioning
*Operant Conditioning
*Habits
*Tasks that can be performed automatically without attention or conscious thought create Habit patterns and movement schema
*Explicit OR Declarative Learning
*Results in Knowledge that can be Consciously Called Upon
*Requires Awareness, Attention, Reflection
*Facts & Instructions
Motor learning is also cognitive with aspects of instruction, translation, imitation, and movement.
People are more likely to use explicit adaptation when given explicit instructions.

Implicit vs. Explicit Learning in Therapy

Depends on the location and type of the central nervous system pathology, where some locations will impair implicit learning, while other locations of damage may impair explicit learning.
Declarative or explicit learning could be useful to rehearse mentally, which can allow increased practice without as much pain or fatigue or therapist time and guidance.

Three Stages of Motor Learning

*Fitz and Posner

Cognitive Stage
*Gather information to understand the nature of the task and characteristics of our performance.
*ATTENTION is required
*Experimental performance
*Large Gains
*Inconsistent Performance
Associative Stage
*Best Strategy is Selected
*Refining Skill with More Practive
*Less Variability & becoming More Consistent
*Conscious Effort
*Smaller Gains
Autonomous Stage
*Performance Seems Unconscious, Automatic & Smooth
*Lower Degree of Attention Required

Burton talks about Mastering Degrees of Freedom. Planes and axes of movement and how much movement and combinations of movement the body needs to control in order to complete a task

Gentile's Two-Stage Model

Describes developing an understanding of task dynamics or requirements of movement to achieve a goal.
Initial Stage: Understanding the purpose of the task, developing movement strategies, and interpreting environmental information.
Second Stage: Redefines movement and develops the capacity to adapt to changes in tasks or settings.

Clinical application and implications

Cognitive phase: explain what you want them to do and the goal of the exercise you have chosen. Do not overload, use positive feedback, and encourage to actively test strategies with limitations.
Associate phase: consider realistic settings and provide some variability in practice, support learners self-analyze, and don't provide feedback too soon.
Autonomous: provide minimal intervention, ensure new goals, and add new complex components.

Other considerations to take in when working with pt's.

Amount of Practice/Practice Levels
Feedback. Type, Frequency and Timing
*Focus instructions and attention
*Active participation and motivation
*Practice Conditions
*Specificity practice - Relevant and Meaningful

Dosage, Feedback, and Attention

Amount of practice or practice levels for dosage includes repetitions such as Frequency, Intensity, Duration, Type.
Frequency and timing of feedback should be intensive and often yet given before, during, and after task completion during cognitive phases where physical feedback and verbal feedback are present. This feedback should be reduced when pts are through the associative and autonomous stages.
Disruptions on performance are found if you think about how you are doing something. Do not overthink and allow the body to use pre-trained programs. Be aware of yips in sports and overthinking.
Meaningful training is important for the pt where practice would involve active problem solving, make mistakes, given possible solutions, and encourage you to purpose them.

Contextual Training

How the magnitude of effect can also depend on variables such as the skill level, demands on task, and amount of the individual.
Blocked Scheduling: requires that all practice be completed under one condition before next.
Random Scheduling: Maximizes variability of training conditions.
Serial Practice Scheduling: Between scheduling.
WHOLE vs PART
*We might need to practice depending on the circumstances or individual. Part of a task or even both can be used.
Environment needs to be relevant for pt, and a task should be specific on the goal that is achieved, and meaningfulness to patients, too. Pt need to pay attention to what the are doing instead of overthinking.
Tasks needs to not be too challenging instead of discouraging, or unsafe. As well as needing to be difficult enough to activate new networks to form.
Transfers should be specific to the goal on task.
Variable Practice in new or variable settings is recommended to ensure effectiveness.

In summary

Rehab needs to be individualized as the Pt's goal and environment.
Target a level of Therapy the pt is engaging in, to where they can pay attention without overthinking on task.
Dosage and Repetition with variability is important, especially with pt fatigue.
Feedback on declarative learning is more on performance where frequencies decrease, and continuous task involve procedural leaning that focueses more on outcomes.
Active problem solving where pt become aware and able to solve their own problems.
Practice, Trial, and Error should be present where pt gets feedback, learns from mistakes, some sort of practice is required, doing something, and gaining feedback which equal to learning.

Motor Learning Concepts and Clinical Relevance

Learning

Learning: A process of acquiring capability for skilled action resulting from experience or practice, inferred by a change in behavior, improved performance, or outcome, producing permanent changes. Involves new strategies for sensing information and includes perception, cognition, and action processes.
Clinical Relevance: Essential for physiotherapists to help patients learn or relearn everyday motor skills, improving skill, maintaining consistent performance, and adapting to changes.

Explicit / Declarative Learning

Definition: Results in knowledge that can be consciously called upon, requiring awareness, attention, and reflection. Involves facts and instructions.
Clinical Relevance: Useful for mental rehearsal, increasing practice without pain or fatigue, and in cases where implicit learning is impaired due to CNS pathology.

Implicit / Non-declarative Learning

Definition: More reflexive and automatic, known as habitual in nature, does not require higher cognition but frequent repetition. Broken down into non-associative, associative, and procedural learning.
Clinical Relevance: Important for training automatic movements and habits, useful when explicit learning is impaired due to CNS pathology.

Non-Associative Learning

Definition: Involves habituation (decreased response to repeated stimulus) and sensitization (increased response to a stimulus).
Clinical Relevance: Habituation can be used to reduce sensitivity to threatening stimuli or movements. Sensitization can be used to increase attention to important sensory cues.

Associative Learning

Definition: Involves classical conditioning (pairing stimuli) and operant conditioning (learning through consequences).
Clinical Relevance: Can be used to associate specific movements with desired outcomes or to reinforce correct motor patterns through rewards.

Procedural Learning

Definition: Learning tasks that can be performed automatically without attention or conscious thought, creating habit patterns and movement schema.
Clinical Relevance: Essential for relearning motor skills, such as walking or reaching, where automaticity is desired.

Amount of Practice - i.e., Dosage

Definition: Includes repetitions, frequency, intensity, duration, and type of practice.
Clinical Relevance: High-intensity, repetitive practice is crucial for neuroplasticity and motor learning, but dosage should be tailored to the patient's fatigue level and capabilities.

Whole vs. Part Practice

Definition: Practicing the entire task versus breaking it down into smaller components.
Clinical Relevance: Whole practice is suitable for simple, discrete tasks, while part practice is better for complex, sequential tasks. Can be used in combination depending on the circumstances or individual.

Massed vs. Distributed Practice

Definition: Massed practice involves short rest periods relative to the trial length, distributed practice is longer.

*Clinical Relevance: Distributed tends to show better overall results in long term retention

Constant vs. Variable Practice

Definition: Constant practice involves repeating the same movement under the same conditions, while variable practice involves performing the movement under varying conditions.
Clinical Relevance: Variable practice enhances generalization and adaptability, important for real-world scenarios. Constant creates better initial performance.

Blocked vs. Random vs. Serial Practice

Definition: Blocked scheduling involves completing all practice under one condition before moving to the next. Random scheduling maximizes variability, and serial practice falls in between.
Clinical Relevance: Blocked practice is useful in the cognitive stage of learning, while random practice promotes retention and transfer in the associative and autonomous stages.

Task Specificity and Transferability

*Definition: Practice conditions should match to the transfer conditions

*Clinical Relevance: Task specific is required to ensure activation of similar brain areas.

Consider Environment / Context and Environment or Task Modification

Definition: Adapting the practice environment and task to meet the patient's needs and promote generalization.
Clinical Relevance: Creating realistic and meaningful practice environments enhances transfer of skills to real-life situations. Tasks should be challenging but not discouraging or unsafe.

Feedback

Definition: Information provided to the learner about their performance, can be intrinsic or extrinsic (augmented).
Clinical Relevance: Essential for error correction and skill refinement. Should be tailored to the learner's stage of learning and the task requirements.

Intrinsic vs. Extrinsic / Augmented

Definition: Intrinsic feedback comes from the individual's sensory systems, while extrinsic feedback is provided by an external source (e.g., therapist).
Clinical Relevance: Extrinsic feedback supplements intrinsic feedback, especially in the early stages of learning. Should be faded as the learner becomes more proficient.

Knowledge of Performance vs. Knowledge of Results

Definition: Knowledge of performance (KP) provides information about the movement pattern, while knowledge of results (KR) provides information about the outcome of the movement.
Clinical Relevance: KP is useful for correcting movement technique, while KR is important for achieving task goals. Both types of feedback are valuable in motor learning.

Concurrent vs. Terminal

Definition: Concurrent feedback is given during the movement, while terminal feedback is given after the movement.
Clinical Relevance: Concurrent feedback can enhance performance but may hinder learning if overused. Terminal feedback allows the learner to process and reflect on their performance