| 1. Research significance and research aimsTheoretical significance: Exploration of human movement coordinationmechanism is one of the most important research parts in the area of skilllearning and control. Work out the core problem of human movementcoordination which is called “freedom of degree”. Hierarchical control theoryhas strong influence on explaining coordination problems. Some of the ideasof movement coordination of hierarchical control theory, which is based onresearch results of simple actions in daily life still need to be verified, theorysystem also should be developed. In order to verify and develop some ideas ofhierarchical control theory in the complex competitive actions as well as eliteathletes. This article explored the law of human movement coordination aboutdiscus action of high level athletes, who have high power and high technicalperformance.Practical significance: Research on special technical feature of eliteathletes have contributed to scientific evaluation of the rationality, perfect andimprove the quality of action, optimization individual technology, monitoring thetraining process, improve the level of training. It also works as scientificsafeguard. One difficult problem is the evaluation of movement coordination.Our research provides reference for diagnosis and the establishment of theevaluation method of human body movement coordination. It reveals thecharacteristics of discus action movement coordination can give theory andmethods to the diagnosis and evaluation of elite discus athletes’ motioncoordination. Discus throwing event has being listed as one of the majornational key scientific and technological projects.Research aims:(1) Reveal the correlation between each element in thediscus throwing movement system.(2) Reveal the correlation between bodyand muscle synergy, and activities and movement tasks, show its basicfunctionality.(3) Reveal its difference in body and muscle synergy, and in activity, and reflect its basic functional optimization performance, in differentdiscus action in the stage of high level.(4) Reveal flexibility of synergy and itsoptimal performance according to variable of important task.(5) Validate anddevelop the viewpoint of hierarchical control in the competitive and complexmovement and in the group of elite athletes.2．Research methodsLiterature: Using relevant words include movement coordination toretrieve various database, include “Chinese Journal Net”,“Wan Fang Data”,“VIP Database for Chinese Technical Periodicals”,“Elsevier Science Full-textDigital Periodicals Data”,“Springer Full-text Digital Periodicals Data”,“EBSCOhost Full-text Database” and “SPORTDiscus Data”. By studying therelevant literature, the author mastered the basic theory related to this topicresearch, the shortcomings of current research and future research trend.Expert interview: On the basis of reviewing relative literature, the authorinterviewed relevant experts on theoretical perspectives which don’tunderstand and research expectations, so as to grasp the present researchingstatus and trends, and the rationality, innovation and reliability of the researchdesign.Data measuring method: Some measurement method is adopted in thissubject to measure elite athletes’ body movement and muscle activity in thediscus action.(1)Application of three-dimensional fixed point videotapemethod, the research Use two high-speed cameras to film excellent discusthrowing athletes in competition and test, then using Ariel motion analysissystem to get body kinematics parameters.(2) Using the FinnishMegaWin6000-16methods of electromagnetic telemetry system to telemeterelectromyography of excellent discus-throwing athletes’12muscles, andobtain the muscle electromyography values.(3) Using two pieces of SwissKistler three-dimensional strain to measure3d ground reaction force thatexcellent discus-throwing athletes get, when they are throwing discuses.Quantization method for core concept of movement coordination of hierarchical control: Some matrix decomposition method is adopted in thisresearch to quantify the key concepts in human movement coordination ofhierarchical control.(1) Functional principal component analysis method isused to quantify motor coordination of body synergies and its activitycoefficient.(2) Nonnegative matrix decomposition method is used to quantifymotor coordination of muscle synergies and its activity coefficient.(3) Usingthe combination of multiple linear regression and the uncontrolled manifoldanalysis method to quantify the index of compensation function duringmovement synergies campaign.Mathematical statistics: In this research, data are processed bydescriptive statistics analysis, correlation analysis, independent sample testson the "t" statistical analysis methods, etc.3．Research conclusionsFramework based on hierarchical control theory, the research discusedthe fundamental functionality and optimization of movement coordination ofbody and muscle synergies in the discus throwing action, and its flexibility andoptimization according to important movement tasks. The study finds that:(1) There are four limbs movement coordination synergies in the discusaction to control the movement of the body. The first movement coordinationsynergy mainly controls the motion of the hip axis. The second movementcoordination synergy mainly controls the relative motion of the shoulder andhip axis. The third movement coordination synergy mainly controls the motionof the shoulder axis. The fourth movement coordination synergy mainlycontrols the relative motion of gravity center of human body and the discus.The movement of these body motor coordination synergies would be able toachieve the rotation of the body parts, reasonable shoulder hip angle andangle of pull, and form the energy transmission between the upper and lowerextremities as well as between the left and right side upper limb, etc..(2) The main activity area of the first movement coordination synergy is inthe second double support phase, the late towards, it focuses on organizing right lateral gastrocnemius, right biceps femoris muscle, left rectus femoris, leftexternal oblique muscle, right bicipital muscle of arm and right wrist flexormuscle in synchrony. The main activity area of the second movementcoordination synergy is in the two single support phases and the seconddouble support phase; it focuses on organizing the lateral of gastrocnemiusmuscle, right biceps femoris muscle, left rectus femoris, left external obliquemuscle, right vertical muscle and right wrist flexor muscle in synchrony. Themain activity area of the third movement coordination synergy is in the twodouble support phase; it focuses on organizing right biceps femoris muscle,the right gluteus, left rectus femoris and right vertical muscle in synchrony. Themain activity area of the fourth movement coordination synergy is in the latefirst single support phase and the flight phase; it focuses on organizing leftlateral gastrocnemius, left biceps femoris muscle, left rectus femoris, leftgluteus and right vertical muscle and left external oblique muscle in synchrony.These movement coordination synergies at every stage of the discusmovement activities closely associated with the movement tasks in thesestages. There is a close correlation relation among the activity in the second,third and fourth kind of movement coordination synergy with performance, inthe discus action.(3) For discus speed, displacement of body center of gravity, displacementof left toe, pull angle, angle of shoulder hip, beneficial variation of movementcoordination synergy activity is in a dominant position, it reflects that in order toensure the fulfillment of these tasks the central nervous system takes Controlof them. In this action, beneficial variation of movement coordination synergiesof left toe displacement and angle of shoulder hip is in a dominant position,among elite athletes. For the discus speed and pull angle, beneficial variationof movement coordination synergy activity is in a dominant position, in thesecond single support and double support phase. For the displacement ofbody center of gravity, beneficial variation of movement coordination synergyactivity is in a dominant position. As the beneficial variation of movement coordination synergy activity is high, it has a high degree of control in the flightphase. However, the low harmful variation of movement coordination synergyactivity causes a high degree of control in the second single support anddouble support phase. The internal and external environment of human bodyhave a different interference in human motion, it causes different controlstrategy of the central nervous system, thus forming the differences.Discus action structure is complicated, high technical, and requires thebody try to exert its power to finish it (competitive purpose). It has certainverification and development for the application of the theory, in this specialaction and in the group of elite athletes. This research believes that:(1) In discus action, a lot of activity in the sport organs may completelyachieve by the flexible combination of a small amount of movementcoordination synergies, which supports the view the control of low level isfinished by movement coordination synergy.(2) In discus action, the movement coordination synergy activity of limbsand muscles is evident in the foundation, to ensure the realization of somemovement subtasks. It supports the view task orientation of movementcoordination synergy activity.(3) As the improvement of sport achievement and sport level, the phase ofmovement coordination synergy activity may also shift, it supports the view thecentral nervous system uses a simple way of movement coordination synergyphase shift to deal with the changes of internal and external constraint ofhuman body. And it embodies the principle of the simplified control. However,in these complex, for the purpose of competitive action, the simple way ofusing the simplified control is not easy to exercise the realization of the task,the central nervous system can properly increase the magnitude to movementcoordination synergy activities and through joint activities of a variety ofmovement coordination to enhance the intensity of individual sports organs.(4) According to some important task variable, beneficial variation ofmovement coordination synergy activity is in a dominant position, in discus action. This support of the central nervous system by using the flexibility ofmovement coordination synergy activities to control important task variable,makes it work smoothly.(5) In discus action, with the sport level improves in the high stage thedominant position of beneficial variation of movement coordination synergyactivity will be enhanced. It comes from the increase of beneficial variation inthe flight phase, the decrease of harmful variation in the second single supportand double support phase. It is not fully consistent with the flexibilitydevelopment theory of movement coordination synergy. |
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