Occupational therapy and application of Motor Control Part II

P.S:As we discussed in the previous article a theoretical reflection of motor Control and motor learning we will be stepping ahead in understanding few more interesting concepts and its application.
In this article i will be providing a few links to highlight on the concept and discuss varied research works and readers will benefit from it only if they read the research links simultaneously with the article as i have tried to summarize with the evidences of excellent work done by researchers.Covering all the literature is beyond the scope of this article so i will be restricting it to few interesting ones.Readers can further do the review.

The challenge of achieving functional skill given neurological disease or injury may be met by weaving key concepts of motor learning and control into treatment protocols. However, in order to effectively integrate these concepts into rehabilitation programs, motor learning and motor control strategies need to be better understood.Individuals with neurological conditions that affect function may need to relearn previously acquired motor skills with an altered number and quality of resources available to them.

Frame work discussed in previous article reflects the fact that in the early 1900's voluntary movement was thought to occur through reflex linkages. This paradigm led to numerous theories of motor control that have been replaced as knowledge of the nervous system as it expands. Although the assumptions associated with varied motor control theories differ, most current theories have incorporated a Systems view of distributed control of the nervous system.
 A Systems model suggests that movement results from the interaction of multiple systems working in synchrony to solve a motor problem 
The advantage of the Systems model is that it can account for the flexibility and adaptability of motor behavior in a variety of environmental conditions. Functional goals as well as environmental and task constraints play a major role in determining movement. This frame of reference provides a foundation for developing intervention strategies based on task goals that are aimed at improving motor skills.

To understand this concept i would request the readers to read the articles that i will be providing link of.
Applying principles of motor learning and control to upper extremity rehabilitation This article from journal of hand therapy has simplified the understanding of the application with a case study.

Moving ahead to another novel concept of Neural Plasticity.
An article published by Center of General Medicine,Belgium as How much brain does a mind need? Scientific, clinical, and educational implications of ecological plasticity. Lebeer J1
 in developmental Medicine and child Neurology,1988 highlights on Ecological Plasticity as a mew paradigm and well does a young brain adapt better than older one.

Leading from this article we will look in to Motor learning and Brain plasticity.

Studies of adult brain plasticity have shown that substantial improvement in function and/or recovery from losses in sensation, cognition, memory, motor control, and affect should be possible, using appropriately designed  training paradigms.

As occupational therapist our aim on functional rehabilitation demands designing treatment strategies beneficial in retraining the individual in his activities of daily living meeting the temporal factors .

 Thus,Driving brain plasticity with positive outcomes requires engaging adults in demanding sensory, cognitive, and motor activities on an intensive basis, in a behavioral context designed to reengage and strengthen the neuro-modulatory systems that control learning in adults, with the goal of increasing the fidelity, reliability, and power of cortical representations.

A randomized controlled pilot study states that brain-plasticity-based intervention targeting normal age-related cognitive decline may potentially offer benefit to a broad population of older adults. Brain plasticity and functional losses in the aged: scientific bases for a novel intervention. Mahncke HW1, Bronstone A, Merzenich MM. (You can mail me for full article PDF)

Thus the neural circuit is a complex process which can be studied in simplified way.To support my discussion i will refer another very recently published article on 30th May 2018 in Journal of Neurophysiology Case Studies in Neuroscience: Evidence of motor thalamus reorganization following bilateral forearm amputations Benjamin P. Whatley , Jeremy W Chopek , Ron Hill , and Robert M. Brownstone 

There are evidences that people who have suffered brain injuries recover their motor function through therapy and training  ( Dimyan and Cohen 2011)
The above mentioned  article highlights a very interesting case study of development of essential tremor ,52 years bilateral forearm amputation due to which he was not able to able to use his prosthesis efficiently and his independence was severely affected.
He was elected for bilateral DBS procedure under micro electrode guidance.As it would be expected to have neuronal firing on active digit or wrist movement this was not possible to test pertaining to amputation however surprisingly it was found that even on volitional contra lateral elbow movement there was no activity observed at Vim however it was found that there was neuronal firing at ventral intermediate nucleus on shoulder protraction ,an action that was used to operate his terminal hooks.this clearly reflects the motor reorganization at thalamus.


This was in reference to motor control and plasticity.Motor learning is one of the widely studied subjects.At present there is no consensus to which motor control theory would define it best.
However as a therapist we should have an insight on this literature before designing our treatment protocols.

I am providing with another article which states the the limitations and clinical implications of all the discussed theories.
Also it discusses the factors affecting motor learning and the application in neuro-rehabilitation.
Theories and control models and motor learning: clinical applications in neuro-rehabilitation.Cano-de-la-Cuerda R et al. Neurologia. (2015)
 Further reflecting on some research work which can be reviewed and referred by readers.
1) Dr Richard Keegan is an Assistant Professor in Sport and Exercise Psychology
Faculty of Health, and Research Institute for Sport and Exercise Sciences,University of Canberra, Australia.

1) Dr. Kristen Pickett who is an Assistant Professor in the Occupational Therapy Program within the Department of Kinesiology at the University of Wisconsin, Madison. She received her Masters in Kinesiology and her PhD in Kinesiology, Biomechanics, and Neural Control from the University of Minnesota, Twin Cities.
You can view her academic tree here https://academictree.org/csd/publications.php?pid=150826&searchstring=&showfilter=all  and read some of her work done in areas of somato sensory and
motor research .

2)Professor Paul Hodge ,Prof & NHMRC Snr Principal Res Fel,School of Health and Rehabilitation Sciences,Faculty of Health and Behavioural Sciences,University of Queensland.directing to his interesting publications.
https://researchers.uq.edu.au/researcher/1050

3)Dr Andrew Gordon,Professor of Movement Sciences,Teachers College,Columbia University.

The Motor Learning and Neuro rehabilitation Lab is coordinated by Dr. Andrew Gordon and Dr. Lori Quinn. Dr. Gordon, Professor of Movement Sciences, is a motor control scientist and is the director of the Center for Cerebral Palsy Research.A highlight of few of his work will give a good understanding of the updates in research

 https://neurotree.org/beta/publications.php?pid=31671  

4)Dr. Simone V. Gill ,PhD,OT,OTR is the director of Motor development Lab,Sargent College,BU Her interests are in the areas of adaptation and development. She is particularly interested in understanding how types of practice and motor experience affect infants’, children’s, and adults’ ability to adapt to change. Her focus is on capturing the trajectory of change over multiple, nested time scales: across sessions, within sessions, within trials, and in the transition from trial to trial. In her current work, she has used walking to examine how infants and adults modify their gait to cope with changes in the environment and with changes in their body dimensions. She is a member of the American Occupational Therapy Association and the Society for Research in Child Development.
Link to her publications/work  https://www.bu.edu/sargent/profile/simone-gill/


I conclude this article in hope of it being beneficial in understanding the concept.However the topic covers a wide area of research and will need constant updates which i will be posting intermittently.
In my next article i will be discussing some cases ad treatement from occupational therapy perspective with evidence based review.

-SSW

Occupational therapy and application of Motor Control Part 1

This article will involve three parts ,for the convenience of readers and better conceptual understanding i am simplifying by starting with the basic understanding of motor control and motor learning and this will be a revision of theory ,subsequent parts will focus on description of its application and recent research work.

What is Motor Control?

-An ability to regulate and direct the mechanisms essential to movement.
The process of initiating, directing, and grading purposeful voluntary movement".

So lets address  how CNS organizes many individual muscles and joints in to coordinated functional pattern? or
How sensory information from body and environment is used to select and control movement?

Physical and Occupational therapists have been referred to as "Applied Motor Control Physiologist"(Brooks 1986) -because we spend considerable amount of time in understanding Motor control problems and as an occupational therapist our therapeutic strategies is directed in improving and retraining the functional movements & patterns.

The organization and production of movement is a complex problem, so the study of motor control has been approached from a wide range of disciplines, including psychology, cognitive science, bio-mechanics and neuroscience.

The control of human movement has been described in many different ways with many different models of Motor Control put forward throughout the 19th & 20th Centuries. Motor Control Theories include production of reflexive, automatic, adaptive, and voluntary movements and the performance of efficient, coordinated, goal-directed movement patterns which involve multiple body systems (input, output, and central processing) and multiple levels within the nervous system

We will be understanding this in detail:

Let us focus on understanding of Movement:
its interaction of movement ,task and the environment

So organization of movement is constrained by factors

• Within Individual
•  the task
• and environment

Within Individual factors that constrain Movement:

Movement and Action
 Movement and Perception
Movement  and Cognition

Task Constraints on Movement

Environmental constraints on Movement

Theories of Motor Control:

Readers can refer to Motor Control, Ann Shumway-Cook  for detailed description:

MOTOR CONTROL THEORIES	AUTHOR	DATE	PREMISE	CLINICAL IMPLICATIONS
Reflex Theory	Sherrington	1906	Movement is controlled by stimulus-response.  Reflexes are basis for movement - Reflexes are combined into actions that create behavior.	Use sensory input to control motor output  Stimulate good reflexes  Inhibit undesirable (primitive) reflexes  Rely heavily on Feedback
Dynamical Systems Theory	Bernstein  Turvey  Kelso & Tuller  Thelen	1967  1977  1984  1987	Movement emerges to control degrees of freedom.  Patterns of movements self-organize within the characteristics of environmental conditions and the existing body systems of the individual.  Functional synergies are developed naturally through practice and experience and help solve the problem of coordinating multiple muscles and joint movements at once.  De-emphasize commands from CNS in controlling movement and emphasize physical explanations for movement.	Movement is an emergent property from the interaction of multiple elements.  Understand the physical & dynamic properties of the body - i.e. Velocity- important for dynamics of movement. May be good to encourage faster movement in patients to produce momentum and therefore help weak patients move with greater ease.
Hierarchical Theories	Adams	1971	Cortical centers control movement in a top-down manner throughout the nervous system.  Closed-loop Mode: Sensory feedback is needed and used to control the movement.  Voluntary movements initiated by “Will” (higher levels). Reflexive movements dominate only after CNS damage.	Identify & prevent primitive reflexes  Reduce hyperactive stretch  Normalize tone  Facilitate “normal” movement patterns  Developmental Sequence  Recapitulation
Motor Program Theory	Schmidt	1976	Adaptive, exible motor programs (MPs) and generalized motor programs (GMPs) exist to control actions that have common characteristics.  Higher-level Motor Programs - Store rules for generating movements.	Abnormal Movement - Not just reflexive, also including abnormalities in central pattern generators or higher level motor programs.  Help patients relearn the correct rules for action  Retrain movements important to functional task  Do not just reeducate muscles in isolation
Ecological Theories	Gibson & Pick	2000	The person, the task, and the environment interact to in uence motor behavior and learning. The interaction of the person with any given environment provides perceptual information used to control movement.  The motivation to solve problems to accomplish a desired movement task goal facilitates learning.	Help patient explore multiple ways in achieving functional task → Discovering best solution for patient, given the set of limitations
Systems Model	Shumway-Cook	2007	Multiple body systems overlap to activate synergies for the production of movements that are organized around functional goals.  Considers interaction of the person with the environment.  Goal-directed Behavior - Task Orientated	Identifiable, functional tasks  Practice under a variety of conditions  Modify environmental contexts

Let's move to concept of Motor Learning

Motor learning is when complex processes in the brain occur in response to practice or experience of a certain skill resulting in changes in the central nervous system that allow for production of a new motor skill.

So ,Motor Control focuses on  understanding of movement already acquired

Motor learning focuses on understanding the acquisition or modification of movement.

• Motor learning research often considers variables that contribute to motor program formation (i.e., underlying skilled motor behaviour), sensitivity of error-detection processes, and strength of movement schemas. There are many different theories of Motor Learning
• Reference:Roller L et al, Contemporary Issues and Theories of Motor Control, Motor Learning, and Neuroplasticity. In: Neurological Rehabilitation 6th Edition. Mosby, 2012. p69 - 105.

Stages of Motor Learning

Stages of Learning	Characteristics	Attention Demands	Activities	Description
Cognitive	Movements are slow, inconsistent and inefficient. Considerable cognitive activity is required.	Attention to understand what must move to produce a specific result. Large parts of the movement are controlled consciously	Practise sessions are: performance focused less variable incorporate a clear mental image (technical & visual).	Early Cognitive; Essential Elements were not observed or not present
				Late Cognitive; Essential elements are starting to appear
Associative	Movements are more fluid, reliable and efficient Less cognitive activity is required	Some parts of the movements are controlled consciously, some automatically.	Practise sessions link performance and results, conditions can be varied. Clear Mental Image = Accurate Performance	Early Associative; Essential elements appear, but not with consistency.
				Late Associative; Essential elements appear regulalry at a satisfactory level.
Autonomous	Movements are accurate, consistent and efficient. Little or no cognitive activity is required.	Movement is largely controlled automatically Attention can be focused on tactical choices	Practise sessions are more results orientated Focus is on greater range of movement, speed, acceleration and use of skill in a novel situation.	Early Autonomous; Essential elements appear frequently avove required level.
				Late Autonomous; Essential elements appear continuously at a superior level.

 There are many different theories of Motor Learning. 

MOTOR LEARNING THEORY	AUTHOR	DATE	PREMISE	CLINICAL IMPLICATIONS
Adams Closed Loop Theory	Adams	1971	Closed Loop - Sensory feedback is used for the ongoing production of skilled movement  Slow movements  Relies on sensory feedback (Sherrington)  Blocked Practice  Errors = Bad! Needs to be accurate!  Memory Trace - Initiation of movement  Perceptual Trace - Built up over a period of practice & is the reference of correctness.   Improvements = Increased capability of performer to use the reference in closed loop	Perform same exact movement repeatedly to one accurate end point  Increase Practice → Increase Learning  Errors produced during learning → Increase strength of incorrect perceptual trace
Schmidt's Schema Theory	Schmidt	1975	Open Loop  Schema - Abstract memory representation for events → RULE  Generalized Motor Program - Rules that allow for the generation of novel movements  Rapid, ballistic movements = recall memory withmotor programs and parameters to carry out movement without peripheral feedback  Variability of Practice → Improve Motor Learning	Optimal Learning → Task practiced under many different conditions  Positive benefits for error production (learn from own mistakes)  Schema has rules for all stored elements, not just correct elements
Ecological Theory	Newell	1991	Based on Systems & Ecological Motor Control Theories  Motor Learning = Increases coordination between perception and action thru task & environmental constraints.  Perceptual-motor workspace - Identifies movemets and perceptual cues most relevant to performance of task  Optimal task-relevant mapping of perception & action → NO Rules!	Patient learns to distinguish relevant perceptual cues important to action.

Theories Related to Stages of learning Motor Skills:

1) Fitts and posner Three Stage Model:(1967)

They suggest there are three main phases involved in skill learning

First stage:

Learner is focused on understanding the nature of task and developing strategies for the same.

Requires high degree of cognitive activity so referred as cognitive stage of learning.

Eg: first day of driving lesson of Mr Ben would require high degree of attention and consious thought

may make a lot of errors in gear shift and ABC control of manual car.

Second stage:

 By this time person has selected best strategy for task and now begins to refine the skill

less variability in performance ,improvement occurs slowly

Referred as Associative stage of learning

Here,verbal/cognitive component not important as focus is on refining a particular pattern than focusing on alternative strategies.

eg: Mr Ben is learning to shuffle from second to third and then first gear as per the speed of vehicle while simultaneously applying ABC control.He is refining on his learned skills

Third stage:

Autonomous stage-there is automacity of skill and involves low degree of attention

Eg: Mr Ben can now enjoy a long drive with friends enjoying on the laughter,talks and the beautiful climate outside.

2)Systems Three Stage model:

Bernstein 1967

3 stages (novice, advanced, expert) theory of motor learning that accounts for reductions in body degrees of freedom seen in child development and new skill acquisition in general. 

The novice stage involves the learner freezing degrees of freedom by co-contracting agonists and antagonists to constrain a joint to simplify the movement, as with the rigid bracing of the wrist when first learning to use a hammer. 

Degrees of freedom are progressively released through the advanced and expert stages enabling movement at more joints and more sophisticated muscle synergies across multiple joints until smooth, coordinated movements are performed. 

3)Gentile two stage Model

1972,1987

this theory of motor skill acquisition describes the goal of learner in each stage.

First stage :involves understanding the goal of the task,developing movement strategies appropriate to achieving goal and understanding environmental features critical to organization the movement.

 -distinguishes relevant/regulatory features from non regulatory

 Second is fixation/diversification stage,goal is to refine the movement.

References:

Ann Shumway Cook,Motor control 4th edition

Science Direct

Physiopedia

In the Next articles i will be discussing on skills and abilities and therapeutic application.

-SSW