NM Lecture 13: Applications of Motor Learning-Relearning Principles

How the brain controls and generates movement.

Use the contemporary systems theory of motor control and examine and treat individuals with neurological impairments using a task oriented approach.

Kelly has not learned the task, because the task was performed with cues, therapist has not witnessed the skill being done by the patient themself.

-> Patient is dependent on the PT or caregiver at the moment

Different.Motor performance-TEMPORARY change in motor performance and occurs at an INSTANT in time. It is directly observable during a practice session. It is defined by variables such as:1) duration to complete a task2) quality of movement3) efficiency in completing the task.

* Improvement in motor performance may be temporary.

PERMANENT change in motor performance, occurs in response to repeated practice. Motor learning is NOT DIRECTLY observable during a practice session. It is inferred based on improved motor performance and assessed indirectly via:

Retention Test, Transfer of learning, and generalizability.

A reassessment of the individuals performance at a later date and after a period of no practice (performance may deteriorate slightly but return to original performance levels after relatively few practice trials).

testing the ability of an individual to successfully perform the learned skill under a variety of different environments.

testing the ability of an individual to apply the learned skills from one task to another new but very similar tasks.

* Use dependent cortical plasticity (positiveplasticity)1)Repetitive active training2) Continued practice* Injury-induced cortical plasticity

It is the sensorimotor cortical representation of the Braille reading finger is expanded in individuals who are blind.

Furthermore, this expanded area fluctuates in size in response to the amount of reading activity the individual engages in. Constraint Induced Movement Therapy (which involves restraining the nonparetic arm and engaging the paretic arm in 6 hours of intensive therapy 5 days a week for 2 weeks), have been shown to demonstrate increased motor map sizes of the paretic finger muscles after treatment. These cortical changes corresponded to improvements to improvements in skilled motor activities and remained relatively unchanged six months after the completion of treatment (i.e.

a retention test demonstrated permanent changes in motor performance).

The cortical motor representation from an immobilized, paretic, or amputated limb will shrink within 4 to 6 weeks post injury related to the decreased use of the neural connections.

1) Early-Cognitive stage2) Intermediate-Associative stage3) Late-automatic/autonomous stage

* self problem solving occurs (figuring out how to approximate the task)*"trial and error" practice leads to variable/ clumsy performance* Heavy reliance on VISUAL input to guide movement (the learner watches how they move; visual feedback is easily brought to conscious attention and it therefore important during early stages of motor learning).*frequent verbal and non-verbal communication is provided by the clinician to describer, demonstrate, or manually guide the desired movement, thus establishing a reference of correctness/cognitive map for the learner (i.e. an internal representation of the ideal performance of the task is created so that the learner has something to compare his or her actual performance to).

*PROPIOCEPTIVE input (instrinsic feedback) important while dependent visual input decreases (propioceptive feedback is less consciously accesible than visual feedback).*performance is refined with less variability and fewer errors.*The clinician should decrease manual guidance and verbal feedback as this will impair learning and promote dependence on the learner on the clinician to perform

*movements become more consistent and are largely error-free.*minimal cognitive involvement (low attention) is required as the task becomes automatic to perform*environmental distractions do not impair performance*attention can be devoted to other things such as scanning the environment for obstacles, talking etc (i.

e. dual task training).* treatment should be aimed at refinement of skills under a variety of different environments (home, work, community)

No, some individuals with TBI may not be able to maintain performance levels when placed in a distracting environment or when asked to perform more than one task at a time (i.e. dual task training).

a. amountb. massed versus distributedc. variable versus constantd. blocked versus randome. part vs.

whole

one of the most important and most intuitive principles of motor learningCIMT takes the principle of practice and repetition to the extreme.CIMT is an example of massed practice (amount of practice time is greater than the amount of rest time). It is used with CP and TBI.Treatment involves restraining the nonparetic hand with a mitt for 90% of waking hours for 14 days in a row. Each day the patient receives at least 6 hours of use of the paretic arm in functional training.

Those that received CIMT performed better on motor function tests than those who received the control treatment (PROM exercises).

Thus permanent changes in performancr occurred and motor learning can be inferred to have taken place in response to the treatment.

Massed Practice: The amount of practice time is greater than the amount of rest time (i.e. CIMT).Distributed Practice: The amount of rest time between trials is equal to or greater than the amount of practice time.

Massed practice appears to have a beneficial effect on motor learning, however fatigue and injury are likely to occur under this type of practice schedule and may potentially mask any learning effects.In addition, the patient must be extremely motivated and have a good attention span and endurance to tolerate the rigors of the training.To enhance motor learning, there is currently not enough evidence to recommend massed over distributed practice with the exception of CIMT.

Variable: Practicing the task under a variety of environment conditions and practicing tasks with similar biomechanics and speed of movement enhances TRANSFER OF LEARNING and GENERALIZABILITY.Constant Practice: Repeated practice of the same task under the same environmental conditions.

To enhance motor learning, variable practice is preferred over constant practice.

May not promote motor learning in individuals with cognitive impairments such as Alzheimer's.These patient's tend to do better when they practice the same task under the same conditions (constant practice). This may be because they are unable to engage in active problem solving or cognitive processes when the environment changes.

Blocked practice: all repetitions of task A are practiced before moving to task B, and all repetitions of task B are practiced before moving onto task C.

Random Practice: No task is repeated two times in a row and the sequence of practice is randomly selected. In other words, perform a single repetition of task A, then a single repetition of task B, then a single repetition of task C, then a single repetition of task B, and so forth (ABC, BAC, CBA, etc.)

Improves short term performance of a task, compromises long term retention of the task (i.e. it compromises motor learning).

Random practice retards initial performance but enhances long term motor learning through trial to trial forgetting and resolving the motor action plan.

Trial to trial forgetting and resolving of the motor action plan. Refered to as contextual interference as it requires more active cognitive thought processes.

1) Initially a short period of blocked practice should occur so that the new skill is roughly approximated (i.e.

during the cognitive phase of motor)2) then random practice should predominate to enhance motor learning.

Variable because it involves multiple skills and changing environment in the same session.

It is blocked practice because of all of the repetitions of one task are performed before the repetitions of the next task are performed.

Practicing complex motor skills in discrete components prior to practicing the entire task.Part-task training is best for serial tasks (i.e.

a task that can be divided naturally into units). Part-task practice should be followed with whole task practice whenever possible.Some examples include:1. how to get out of a wheelchair2.

transfers

Practicing complex motor skills in their entirety. Whole task training is best for tasks that are short movement durations and for continuous motor skills that are cylindrical and rhythmic in nature (i.e. tasks that require a high degree of spatial and temporal coordination.Examples include:WalkingSwimmingWhole task training may not always be appropriate (low level patients) but should be instituted as soon as possible.

Body-weight Support Treadmill Training (BSWTT) - motor-driven treadmill and suspension system that allows for upright posture and uninterrupted repetitions of complete gait cycles.Over time as gait improves, body weight support is gradually reduced to allow for full weight bearing during treadmill walking.Has been shown to be superior to treadmill training with no support because it allows for a more natural, continuous walking pattern and is thus more task-specific.

Whole task practice for continuous cyclical tasks, repetition, and task specificity.1) improve gait performance in a number of different patient populations including-spinal cord injury-stroke-Parkinson's disease-TBI-orthopedics

the central pattern generators (CPG's).

Intrinsic Feedback and Extrinsic Feedback

*knowledge of results (KP)*knowledge of performance (KP)

Intrinsic FB is generated from within the individual during the movement and includes visual, auditory, and somatosensory FB.Intrinsic FB allows for error detection and therefore fosters Independent problem solving.This process aids in establishing an internal reference of correctness whereby a cognitive map or memory of the movement is created.This memory is then used in future practice to detect and correct movement errors.

Extrinsic FB is additional or augmented information about the movement provided from an external source (i.e.

the therapist or coach).Extrinsic FB can be delivered verbally, visually (i.e. demonstration, videotape of performance), or manually. In addition performance outcome measures can be used to provide objective FB.Extrinsic concurrent FB: Given during the task.

Extrinsic terminal FB: Given after the task is completed.

Knowledge of results- KR is a type of extrinsic FB. It is delivered verbally and relates to the outcome of movement and whether there was success in meeting the goal.Knowledge of performance- KP is a type of extrinsic concurrent or terminal FB.

It is also delivered verbally, relates to movement pattern (i.e. kinematic FB). It informs your patient on how to perform the task better for the next practice trial.KP increases motivation and alertness to the task at hand.

High frequency FB (both concurrent & terminal) improves immediate performance but hinders long-term motor learning.Why? Less feedback and problem solving by the patient's self is better for motor learning.

1) Immediate Post response FB2) Summary FB *3) Faded FB *4) Bandwidth FB *Summary FB, Faded FB, and Bandwidth FB enhance long term learning and degrade initial performance.

When determining the amount of FB to deliver to your patient you must consider the stage of motor learning (i.e.

Early- cognitive, more frequent FB may be necessary to help them develop a reference of correctness. As soon as your patient has a general idea of what the movement is, FB should be withheld.

* Provides information to the learner regarding how the movement should be performed and corrected (reference of correctness)* Keeps the learner on the target*motivates the learner

*Too much feedback interferes with the learners ability to self-detect errors*too much FB degrades permanent learning.*too much FB creates performance dependency

The closer you stimulate the actual task and/or environment, the better the transfer of learning.

Rehersal of a task without physical activity (mental imagery).

There is no performance to observe but mental practice has been shown to have positive effects on motor learning.Mental practice should not replace physical practice but be an adjunct. It is likely to be more effective after the individual has developed a basic understanding of the movement (i.e. during the associate stage of motor learning).A Clinical note: mental practice can be used for patients who are in a spinal or cerebral shock.

It can also be useful as part of a home exercise program outside of rehabilitation sessions particularly if safety is a concern. Mental practice may not be suitable for patients with cognitive impairment.

Manual guidance during rehabilitation is often used minimize error, prevent injury, and reduce fear. Too much however reduces the learner's ability to actively problem solve and "trial and error" experiences.Clinical Note: Motor learning theorists recommend using guidance only during the early practice sessions to familarize the individual with the task.

In addition, it should be ideally interspersed with active (hands-off) practice trials to avoid performance dependenct. However, never compromise patient safety.

difficult tasks are interspersed with easier tasks so that feelings of achievement are experienced throughout the session. The role of the clinician is to be a motivator, which in turn will encourage your patient to comply with practice at the clinic and at home.