Regulation of pendulum length as a control mechanism in performing the backward giant circle in gymnastics.

Seven female elite gymnasts performed backward giant circles on the high bar under different conditions of loading. The magnitude (2 or 4 kg) and location (shoulders, waist, and ankles) of load systematically influenced the overall swing duration as well as the relative timing of movements at the joints. An analysis of the mechanical constraints operating suggested that the gymnast should be considered as a pendulum of variable length. Increasing and decreasing pendulum length at appropriate phases of the swing effectively allows energy to be injected into the system, thereby compensating the energy lost to friction. A sharp negative peak in the relative rate of change of pendulum length, characteristic of the upward swing phase of all gymnasts, was found to invariably occur at a particular value of the first-order time-to-closure of the body orientation gap with respect to the vertical. The presence of this invariant suggested that the gymnasts organize their behavior on the basis of such a first-order temporal relation.

[1]  N. A. Bernshteĭn.  The co-ordination and regulation of movements , 1967 .

[2]  D. S. D. Stilling,et al.  Controlling angular oscillations through mass reconfiguration: a variable length pendulum case , 2002 .

[3]  R J Bootsma,et al.  Acquiring an attacking forehand drive: the effects of static and dynamic environmental conditions. , 1991, Research quarterly for exercise and sport.

[4]  R J Bootsma,et al.  The effects of task constraints on the organization of interception movements. , 1997, Journal of sports sciences.

[5]  A Arampatzis,et al.  Mechanical energetic processes during the giant swing exercise before dismounts and flight elements on the high bar and the uneven parallel bars. , 1999, Journal of biomechanics.

[6]  F. C. Bakker,et al.  Catching balls: how to get the hand to the right place at the right time. , 1994, Journal of experimental psychology. Human perception and performance.

[7]  B G Bardy,et al.  How is body orientation controlled during somersaulting? , 1998, Journal of experimental psychology. Human perception and performance.

[8]  Alfred W. Hubbard,et al.  Visual Movements of Batters , 1954 .

[9]  Michael J. Hiley,et al.  Optimum Technique for Generating Angular Momentum in Accelerated Backward Giant Circles Prior to a Dismount , 2003 .

[10]  A. Chardenon,et al.  The perceptual control of goal-directed locomotion: a common control architecture for interception and navigation? , 2004, Experimental Brain Research.

[11]  W H Warren,et al.  Visual control of braking: a test of the tau hypothesis. , 1995, Journal of experimental psychology. Human perception and performance.

[12]  David A. Winter,et al.  Biomechanics and Motor Control of Human Movement , 1990 .

[13]  M. Turvey.  From Boreli (1680) and Bell (1826) to the Dynamics of Action and Perception. , 1994, Journal of sport & exercise psychology.

[14]  B. Kay,et al.  Infant bouncing: the assembly and tuning of action systems. , 1993, Child development.

[15]  P. Tea,et al.  Pumping on a Swing , 1968 .

[16]  R. J. Bootsma,et al.  Coordination in prehension Information-based coupling of reaching and grasping , 1998, Experimental Brain Research.

[17]  David N. Lee,et al.  Plummeting gannets: a paradigm of ecological optics , 1981, Nature.

[18]  T. Mexia,et al.  Author ' s personal copy , 2009 .

[19]  M J Hiley,et al.  The margin for error when releasing the high bar for dismounts. , 2003, Journal of biomechanics.

[20]  A Arampatzis,et al.  Mechanical energetic processes during the giant swing before the Tkatchev exercise. , 2001, Journal of biomechanics.

[21]  W. H. Warren.  The dynamics of perception and action. , 2006, Psychological review.

[22]  W. Warren.  Action modes and laws of control for the visual guidance of action , 1988 .

[23]  Michael J. Hiley,et al.  The mechanics of the backward giant circle on the high bar , 2000 .

[24]  R. Schmidt.  A schema theory of discrete motor skill learning. , 1975 .

[25]  Vladimir M. Zatsiorsky,et al.  The Mass and Inertia Characteristics of the Main Segments of the Human Body , 1983 .

[26]  D. Ingle,et al.  Brain mechanisms and spatial vision , 1985 .

[27]  Tang Yun-xia.  The Changes of Men's Gymnastics Competitions Code of Points and Prospect of Competition in 2006 , 2006 .

[28]  Maurice R Yeadon,et al.  Maximal dismounts from high bar. , 2005, Journal of biomechanics.

[29]  W. H. Warren,et al.  Visual control of step length during running over irregular terrain. , 1986, Journal of experimental psychology. Human perception and performance.

[30]  G. Montagne,et al.  A Robust Solution for Dealing With Environmental Changes in Intercepting Moving Balls , 2005, Journal of motor behavior.

[31]  R. Bootsma,et al.  On the information-based regulation of movement: What Wann (1996) may want to consider , 1997 .

[32]  E. Werner.  Children of the Garden Island. , 1989, Scientific American.

[33]  Vladimir M. Zatsiorsky,et al.  Kinetics of Human Motion , 2002 .

[34]  D. Robertson,et al.  The kinematics, movement phasing and timing of a skilled action in response to varying conditions of uncertainty , 1985 .

[35]  R. Bootsma,et al.  Timing an attacking forehand drive in table tennis. , 1990 .

[36]  David N. Lee,et al.  Visual Timing in Hitting An Accelerating Ball , 1983, The Quarterly journal of experimental psychology. A, Human experimental psychology.

[37]  Juan R. Sanmartin,et al.  O Botafumeiro: Parametric pumping in the Middle Ages , 1984 .