Exercise prescription to maximize usedependent neuroplasticity Patrick Grabowski MPT, PhD Board Certified Clinical Specialist in Orthopaedic Physical Therapy Assistant Professor of Physical Therapy University of Wisconsin La Crosse Objectives: Identify clinically important elements of current theories of motor control and learning Discuss elements of neuroplastic adaptation common in many clinical presentations Demonstrate clinical application of factors known to influence use-dependent neuroplasticity A word on evidence Evidence-based versus Evidence-bound Evidence is only one piece of the puzzle Use best available evidence to innovate 1
What is the study of Motor Control? Neuroscience Psychology Biomechanics Motor Control Reflex Theory Combined action of individual reflexes explains complex behavior. Hierarchical Theory Higher centers are always in control & reflexes are nested within organized levels of the CNS 1 2
Motor Program Theory Motor Programming - a command center in the brain makes decisions on movement Motor program abstract representation of movement plan, stored in memory, contains all commands required to carry out intended action Motor Program Theory Generalized motor program - A class of actions or patterns of movement that can be modified to yield various response outcomes. Execution of GMP 1. Make decision to act 2. Retrieve the appropriate generalized motor program from memory 3. Add the estimated parameter values to achieve the desired outcome in advance 4. Send signal to move 3
2 Dynamic Systems Theory Skilled action emerges from dynamic interaction of numerous variables in body, environment and skill Dynamic Systems Theory Self-organization De-emphasizes the nervous system Constraints Boundaries that influence movement capabilities Internal: state of body s subsystems External: the task and the environment 4
Dynamic Systems and Movement variability Optimal window of variability Important for exploration, distribution of tissue stress, and flexibility to adapt to an ever changing environment Consequences of lack of movement variability Task-Oriented Approach Normal movement emerges as interaction of multiple systems, organized around behavioral goal Movement we see is not only a result of impairment but attempts of other systems to compensate Task-Oriented Approach * 1 5
From control to learning Schema Theory Learning consists of ongoing updates to recall and recognition schema, which interact with the generalized motor program Ecological Theory Perception and action coupling underlies motor learning Learning = a constant matching of: Motor output Perception (sensory input + interpretation) Motor learning = trial and error: with every movement sensory information is used to update motor responses 6
Stages of Learning Fitts and Posner Stage 1: Cognitive Stage 2: Associative Stage 3: Autonomous 1 Systems 3 Stage Model 3 stages controlling degrees of freedom Novice Advanced Expert Summary of motor control and learning Movement is developed and refined through perceptual motor mapping process, and is constrained by task, individual, environment 7
What changes with learning? Movement Attention Error detection and correction The nervous system Simple plasticity-habituation 1 Simple plasticity-sensitization EPSP 1 8
Plasticity in motor learning Involves multiple areas, including: Cerebellum Sensorimotor cortex Basal ganglia Parietal structures Spinal cord Plasticity in motor learning Initial phase of learning Widely distributed activation Bilateral cortex, basal ganglia, cerebellum Later phases of learning Less cortical activity & more subcortical Basal ganglia, cerebellum, thalamus Plasticity in motor learning Role of cortical areas: Cortex more involved early in learning Cortical representation in healthy persons is constantly changing in response to activity, behavior, and skill acquisition 9
Novice performance is correlated with increased brain activity 3 Recovery of Function Changes in cortical maps Changes in cortical maps also occur after peripheral injury or CNS injury 4 10
Severity of PCS is correlated with increased brain activity 5 5 6 11
7 8 9 12
The correlates of cortical change have been shown Bilateral pathology Altered pressure/pain thresholds Altered thermal sensitivity (inconsistent) Altered performance on laterality tests of reaction time 10 Recovery of Function Individual constraints are altered Recovery can be viewed as motor learning with a new set of constraints Principles of Plasticity 11 13
How many?... Neuroscience suggests from 1,000s (UE) to 10,000++ (LE) to create neuroplastic response Doyon et al, 1997, Pavlides et al, 1993, Nudo et al, 1996, Karni et al, 1995, Chau et al, 1998 12 13 14
Repetition matters 14 15
Specificity Skill learning associated with cortical reorganization Simple exercise and strength training not enough 15 16
Specificity Make unskilled movements more skilled by making them goal-directed with accuracy requirements Activity take one basic UE and one basic LE exercise and consider ways to alter it Salience Skills practiced must be of sufficient importance 16 17
17 Salience Strive to implement patient-specific exercise 18
Use it and improve it: Cardiovascular exercise Cardiovascular exercise increases BDNF Cardiovascular exercise facilitates skill acquisition and retention Cardiovascular exercise increases BDNF High intensity cycling facilitated retention of motor skill 18 Moderate intensity cycling facilitated acquisition of motor skill 19 19
Number of subjects Grabowski et al. 2018 (in prep) Retention of learned hip flexion angles during landing 10 Retention of PHFA Retention 10 No Retention * NNT=3 5 9 14 7 6 7 Control Low Moderate High Exercise Intensity Use it and improve it: Cardiovascular exercise Moderate intensity (some evidence for high) Before or after practice Single/acute and chronic effects Activity Consider how you could fit this in your normal clinical workflow Harnessing plasticity: What s next? Genetically individualized rehabilitation Neuroplasticity modulated by BDNF, dopamine, others Multiple alleles and their methylation profiles determine amounts present May determine amount of plasticity (both positive and negative) 20
Summary Ideas discussed: High repetition Goal-directed movements Patient-specific exercise Use cardiovascular exercise Summary Plasticity underlies motor learning/recovery of function Using some principles from our understanding of motor control, and a little creativity, may improve chances of harnessing plasticity References: 1. Shumway-Cook, A., & Woollacott, M. H. (2017). Motor control: translating research into clinical practice. 5 th edition. Lippincott Williams & Wilkins. 2. Mulder, Theo. "A process-oriented model of human motor behavior: toward a theorybased rehabilitation approach." Physical therapy 71.2 (1991): 157-164. 3. Gobel, Eric W., Todd B. Parrish, and Paul J. Reber. "Neural correlates of skill acquisition: decreased cortical activity during a serial interception sequence learning task." Neuroimage 58.4 (2011): 1150-1157. 4. Purves, D., Augustine, G. J., Fitzpatrick, D., Hall, W. C., LaMantia, A. S., McNamara, J. O., & White, L. E. (2014). Neuroscience, 2008. De Boeck, Sinauer, Sunderland, Mass. 5. Smits, Marion, et al. "Postconcussion syndrome after minor head injury: brain activation of working memory and attention." Human brain mapping 30.9 (2009): 2789-2803. 6. Napadow, Vitaly, et al. "Somatosensory cortical plasticity in carpal tunnel syndrome a cross-sectional fmri evaluation." Neuroimage 31.2 (2006): 520-530. 7. Lotze, Martin, and G. Lorimer Moseley. "Role of distorted body image in pain." Current rheumatology reports 9.6 (2007): 488-496. 21
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