Movement System Variability

Keith Davids, PhD, is dean of the School of Physical Education at the University of Otago in New Zealand. He has taught and conducted research in the field of motor learning and control for 25 years. In addition, he has produced three books in this area and authored numerous chapters and articles for journals. Davids has worked in higher education in both Europe and New Zealand. He is currently a co-editor of the International Journal of Sport Psychology and received a PhD in motor control from Leeds University, UK, in 1986. Simon Bennett, PhD, has taught and conducted research in the field of motor control for over 10 years. He is a senior lecturer in Motor Control at Manchester Metropolitan University, UK, where he also serves as research team leader and laboratory director. Bennett received his PhD from Manchester Metropolitan University. A few of Bennett's research interests include specificity of learning, coordination dynamics, information sources for interceptive actions, intermittent vision, ventral and dorsal processing, and observational learning. He has co-authored several chapters and articles for journals in this field. Karl Newell, PhD, is associate dean for research and graduate education in the College of Health and Human Development at Penn State University. He has conducted a long-standing research program on the role of movement variability in motor control and has helped create a new way to think about movement variability. Newell is former editor of the Journal of Motor Behavior and served as president of the North American Society for Psychology of Sport and Physical Activity.

Part I: Behavioral Analysis of Variability in the Movement System Chapter 1. Variability in Motor Output As Noise: A Default and Erroneous Proposition? Karl M. Newell, PhD, Katherine M. Deutsch, PhD, Jacob J. Sosnoff, PhD, and Gottfried Mayer-Kress, PhD -Noise and Movement Variability in Information Theory -Noise in Physiological Models of Motor Control -Categories of Noise -Variability and Noise in Motor Output -Multiple Time Scales of Variability -Concluding Comments Chapter 2. Variability in Postural Coordination Dynamics Olivier Oullier, PhD, Ludovic Marin, PhD, Reinoud J. Bootsma, PhD, Thomas A. Stoffregen, PhD, and BenoA?A?A"t G. Bardy, PhD -Ambiguity of the Neurophysiological Approach to Postural Coordination -Kinematic Analysis of Dynamic Patterns in Postural Coordination -Postural Coordination Emerges from the Interplay of Different Constraints -Intention (to Sway) Modulates the Stability of Postural Coordination -Dynamics of Postural Transitions -Nature of the Transitions Between Postural Coordination Patterns -Variability in Self-Organization of Postural Coordination -Unique Aspects of Postural Coordination -Conclusion -Acknowledgements -Footnotes Chapter 3. The Interface of Biomechanics and Motor Control: Dynamic Systems Theory and the Functional Role of Movement Variability Paul S. Glazier, Jonathan S. Wheat, PhD, David L. Pease, and Roger M. Bartlett, PhD -Movement Variability: Traditional and Contemporary Approaches -Biomechanics and Motor Control -Sports Biomechanics: A Critical Overview -Dynamic Systems Theory Applied to Sport Biomechanics -Concluding Remarks Part II: Variability, Performance and Excellence Chapter 4. Serving Up Variability and Stability Craig Handford, PhD -Deliberate Practice Is Not Always About Movement Consistency -Solutions to Movement Problems Can Be Generic and Yet Individual -Variability Can Provide a Basis for Practice in Parts -Conclusion Chapter 5. Variability in Motor Output and Olympic Performers Les G. Carlton, PhD, John W. Chow, PhD, and Jaeho Shim, PhD -Variability in the Motor Domain -Speed and Accuracy in Projectile Tasks -Models of Throwing Accuracy -Throwing Accurately to Horizontal Targets -Throwing Accurately to Vertical Targets -Speed-Variability Trade-Offs in Sport Tasks -Speed and Variability in Throwing Tasks -Speed and Variability in Striking -Summary -Olympic Project -Data Collection -Location of Ball Landing -Ball and Racket Speeds -The Olympic Project and Speed-Accuracy Trade-Offs Chapter 6. Genetic and Environmental Constraints on Variability in Sport Performance Joe Baker, PhD and Keith Davids, PhD -Nurture Perspective of Expertise Development: Deliberate Practice -Challenges of Deliberate Practice -Genetic Constraints on Physical Performance -Genetic Contribution to Motor Skill Performance -Genetic Contribution to Variability in Physical Performance -Concluding Remarks: A Case for Dynamic Systems Theory Part III: Issues in Measurement Chapter 7. Coordination Profiling of Movement Systems Chris Button, PhD, Keith Davids, PhD, and Wolfgang SchA?A?A"llhorn, PhD -Theoretical Evolution of Variability in Movement -Data Collection and Statistical Analysis -Coordination Profiling -Cluster Analyses and Time-Continuous Variables of Intra- and Interindividual Athletic Performance -General Discussion and Implications Chapter 8. Clinical Relevance of Variability in Coordination Joseph Hamill, PhD, Jeffrey M. Haddad, MS, Bryan C. Heiderscheit, PhD, Richard E.A. Van Emmerik, PhD, and Li Li, PhD -Variability in Traditional and Dynamical Systems View -Dynamic Systems Concept of Variability in Movement -Clinical Relevance of Variability -Conclusions Chapter 9. Measuring Coordination and Variability in Coordination Jonathan S. Wheat, PhD and Paul S. Glazier, PhD -Measuring Coordination and Variability in Coordination -Summary Part IV: Variability Across the Lifespan Chapter 10. Functional Variability in Perceptual Motor Development Geert J.P. Savelsbergh,PhD, John van der Kamp, PhD, and Karl S. Rosengren, PhD -Functional Coupling of Perception and Movement: Constraints -Variability in Early Infant Reaching -Functional Variability and Exploration -Variability and Selection in the Coupling of Information and Movement -Conclusions Chapter 11. Aging and Variability in Motor Output Evangelos A. Christou, PhD and Brian L. Tracy, PhD -Older Adults Do Not Always Exhibit Greater Variability in Motor Output Within a Trial -Older Adults Exhibit Greater Variability in Motor Output From Trial to Trial -Physical Training Attenuates the Variability of Motor Output in Older Adults -Changes in the Nervous System Alter Variability in Motor Output -Summary Part V: Variability Within Subsystems Chapter 12. Mechanical Properties of Muscles Reduce Performance Variability Alberto Minetti, MD -Arm Wrestling -Variability in Drop Landing -Conclusions Chapter 13. Cellular and Molecular Basis of Heterogeneity in Contractile Performance Variability Carlo Reggiani, PhD and Susan Bortolotto, PhD -Functional and Molecular Heterogeneity of Muscle Fibers -Functional Characterization of Human Muscle Fiber Types: Contractile Properties -Heterogeneity of Electrophysiological Properties and Excitation-Contraction Coupling in Human Muscle Fibers -Metabolic Heterogeneity of Human Muscle Fibers -Plasticity of Human Skeletal Muscles -Optimization of Muscle Performance by Selective Recruitment -Conclusions Chapter 14. Self-Organizing Brain Dynamics and Movement Goals Walter Freeman, MD -Limbic Contributions to Intentional Action -Neurodynamics of Chaos in Perception -Conjoining of Time and Space Through Action -Linear Causality Versus Circular Causality -Timing in the Awareness of Action -Conclusion Chapter 15. Variability of Brain Activity During Rhythmic Unimanual Finger Movements T.D. Frank,PhD, C.E. Peper, PhD, A. Daffertshofer, PhD, and P.J. Beek, PhD -Theoretical Framework -Coordinated Rhythmic Movements -Experiments and Experimental Results -Dominance of Descending Neural Activity -Phase Synchronization and Mean-Field Forces -Connectivity Maps -Mean-Field Haken-Kelso-Bunz Model -Implications for the Dynamic Systems Approach -Outlook