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60CHINESE WOMAN WEIGHTLIFTER SNATCH EXCELLENT BIOMECHANICAL ANALYSIS TECHNOLOGY
Wang Xinna Hebei institute of Physical Education China Kharkiv State Akademy of Physical Culture(Ukraine)
Annotation. JVC9800 camera using a sentinel site in the tournament seven of China’s best athletes in women’s weightlifting snatch filming techniques, shooting a frequency of 50 cells / s, exposure time 1 / 250 s. PEAK video analysis system used for the video shoot for processing. Analysis of the athletes in the snatch during the knee angle and hip angle, trunk angle and time-varying relationship between the curves, revealing the excellent Chinese women’s weightlifting snatch the technical characteristics of the athletes.
Key words: women; weightlifting; snatch; sports biomechanics; technical analysis
Анотація. Ван Сіньна. Китайські жінки у важкій атлетиці -біомеханічний аналіз техніки рухів. Представлено результати відеозйомок камерою JVC9800 техніки семи кращих спортсменок Китаю в жіночій важкій атлетиці на турнірі. Зйомка проводилась із частотою 50 кадрів/с, час експозиції 1/250с. Для обробки використалася PEAK відео система аналізу зйомок. Аналіз руху спортсменок у змінах кута в колінному й тазостегновому суглобах, кута нахилу тулуба, а також часу в різні моменти між кривими руху, дозволив визначити кращі оптимальні технічні характеристики.
Ключові слова: жінки, важка атлетика, ривок, спортивна біомеханіка, аналіз техніки.
Аннотация. Ван Синьна. Китайские женщины в тяжелой атлетике - биомеханический анализ техники движений. Представлены результаты видеосъемок камерой JVC9800 техники семи лучших спортсменок Китая в женской тяжелой атлетике на турнире. Съемка производилась с частотой 50 кадров/с, время экспозиции 1/250с. Для обработки использовалась PEAK видео системы анализа съемок. Анализ движения спортсменок в изменениях угла в коленном и тазобедренном суставах, угла наклона туловища, а также времени в различные моменты между кривыми движения, позволил определить лучшие оптимальные технические характеристики.
Ключевые слова: женщины, тяжелая атлетика, рывок, спортивная биомеханика, анализ техники.
© Wang Xinna, 2009
Introduction
International Olympic Committee since 1996 as the Summer Olympic Games women’s weightlifting competition will be included in the 2000 Sydney Olympics, the women’s weightlifting has been the rapid development of the project. Technical action weightlifting snatch and clean and jerk at two athletes to snatch fast, continuous action will be referred to bar Taiwan from weightlifting straight arm movements in the head and legs straight, feet standing on a horizontal position, maintaining that state of complete stability. It is the first weightlifting moves, but it is also a very strong technical action, action snatch a direct impact on the final results to weightlifting. Into the past several decades, experts and scholars at home and abroad to adopt more advanced technology research method of weight lifting, weight training methods research. However, most of the clean technology research, to snatch a relatively small technology only for technical tests of statistical indicators. Lack of technique and movement to reveal the theoretical analysis of biomechanics. Therefore, we will snatch technology players throughout the process of technical indicators and analysis of statistics.
Research purposes
In this study, in reference to research results and experience of our predecessors on the basis of the method of using video analysis of China’s best athletes in women’s weightlifting competition in the technical analysis of movement in order to reveal the Chinese women’s weightlifter snatch excellent technical features, at the same time strive to IT services means there is a new breakthrough for the coaches and athletes training for the provision of simple and practical, effective means of testing scientific training. Weightlifting snatch of biomechanical characteristics of movement to explore and study the level of play for them to provide research and technology protection.
Research results
To participate in the National Championship in 2007, the women’s snatch at all levels to carry out performance analysis of the first athletes, the basic conditions in Table 1.
Table 1
The basic situation of the study
Name snatch-level results
Yang Lian 48kg 96 kg
Xiong Li 53kg 98kg
Jiang Jingjing 58kg 98kg
ShuJiean 63kg 110kg
LuLisha 69kg 118kg
SunRuiping 75kg 75kg
Zhang Zheng 75+kg 131kg
Stages of Action
In order to facilitate the scientific, technical and detailed analysis of the snatch action, this action also in this study is divided into five stages. (1) preparatory stages: from the athletes to grasp barbell chest natural legs open ready to bell. (2) to bell stages: from the
barbell from the start to the largest extensor moment (the maximum angle of knee joint) end of the extension to the so-called bell action. The largest angle from the knee extensor moment to moment cited the largest knee (knee angle minimum) concluded that the cited reference bell knee action. (3) force phase: the knee joint angle of knee cited the greatest moments from the beginning to the barbell at all times to maximize the speed of the end of that phase of the largest force. (4) Squat support phase: the maximum speed from the barbell to the barbell at all times the highest point of the end. (5) rose stages: from the squat to stand up to all the body.
Barbell snatch the process of vertical velocity and physical focal point for the study on the relationship between joint angle
Projects in the weightlifting snatch technique, the athletes body hip angle, knee angle change on the success or failure of actions and the vertical bar has a direct impact speed.
Knee angle curve over time
Analysis of samples found in the snatch technique, off from the barbell to the barbell until then athletes, athletes knee angle curve over time showed two peaks plus one valley (see Figure 1-7), two peaks corresponding to force the two athletes, a trough primers corresponding knee action athletes.
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Fig. 1. Yang Lian knee angle in time of cun’e
Time (sec)
Fig.2. Xiong Li knee angle in time of curve
Knee technology primers snatch technique is very important, citing knee action is in place to affect a large extent after the completion of action. The first of two peaks with the athletes and the speed of force to accelerate the increase in the slope of the corresponding, when the knee angle of the first two peaks in maximum speed reached the maximum value. From the test data can be seen from the perspective of six athletes were extensor 168.5 degrees, 175 degrees, 163.6 degrees, 161 degrees, 158.7 degrees, 157.9 degrees, 160.6
degrees, extension in place, and action to complete than good leg strength brought into full play, directly for the second time a force fully prepared to do.
Time (sec)
Fig. 3. Jiang Jingjing knee angle in time of curve
Time (sec)
Fig. 4. Shu Jiean knee angle in time of cun’e
Time (sec)
Fig. 5. Lu Lisha knee angle in time of cun’e
Time (sec)
Fig. 6. Sun Ruiping knee angle in time of cun’e
Tims (sec)
Fig. 7. Zhang Zheng knee angle in time of curve
Hip angle curve over time Can be found from Figure 8-14, in the snatch move the completion of the technical process, the athlete’s hip joint angle changes with the passage of time is always increasing, only a peak, that is, the second force in the Department. In the entire hip joint angle changes in snatch action is very large, reaching about
150 degrees. The adequacy of the hip extension has become the second force to measure the effectiveness of a standard. Through the study found that the time to open the hip joint will affect the completion of the entire movement. Snatch of elite athletes for the technical performance of the first stage of the main force to complete action on extensor, trunk changed little action until the beginning of primers knee and hip was quickly opened.
Time (sec)
Fig. 8. Yang Li an hip angle in time of cun’e
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Fig. 9. Xiong Li hip angle in time of cun’e
Time (sec)
Fig. 10. Jiang Jingjing hip angle in time of cun’e
Time (sec)
Fig. 11. Shu Jiean hip angle in time of cun’e
Time (sec)
Fig.12. Lu Lisha hip angle in time of curve
From Figure 6 in the hip joint angle curve over time can be seen, from off the bar to force the first stage, the rate of change of hip joint angle smaller than curve More gentle. The force from the first force to the second end of the beginning of this stage, the rate of change of hip joint angle larger on the hip movement in
the snatch force the second phase play a major role. We can see that the center vertical barbell velocity knee in place from the beginning of primer to the second force the pace of the end of this stage the rate of change of the largest centers barbell vertical velocity, knee angle and the angle between the hip at the same time, made in the second power stage of the athletes knee and hip joints fully extended is the greatest weight to enhance the speed of the main factors.
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Fig. 13. Sun Ruiping hip angle in time of cun’e
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Fig.14. Zhang Zheng hip angle in time of curve
Trunk angle curve over time Trunk angle is the hip joint with the shoulder of the two-point connection with the horizontal angle. The point of view may reveal the athletes in the trunk during the snatch technique of pitching situation. From the trunk angle curve over time can be seen(see Figure 15-21), the trunk angle first and then gradually increased to reduce.
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Fig. 15. Yang Lian trunk angle in time of curve
Mainly due to the weight force of the first phase to be completed by the extensor movements, the trunk can not be stressed too early, so the leg strength in order to give full play to the very beginning, however, reduced the trunk angle. Citation knee action from the beginning to the end of the second force this stage, the trunk angle increase is due to the development of hip joint force to fight the reasons. This is hip once again the second time in the weight lifting force plays an important role.
Time (sec)
Fig. 16 Xiong LI trunk angle in time of curve
Time (sec)
Fig. 17. Jiang Jingjing trunk angle in time of cun’e
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Fig. 18. Shu Jiean trunk angle in time of curve
Time (sec)
Fig.19. Lu Lisha trunk angle in time of curve
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Fig. 20. Sun Ruiping trunk angle in time of cun’e
Time (sec)
Fig. 21. Zhang Zheng trunk angle in time of curve
Conclusion
By studying the body posture angle and the relationship between technology found in the snatch, snatch technique in the process, the knee angle changes over time double peaks: the hip joint angle changes with time curve for the increasing trend, showing a single peak; trunk angle changes over time laughing stock of the performance for the first increase in a single peak curve. Bell to the main course of action to be completed by the extensor, trunk changed little action until the beginning of primers knee and hip was quickly opened.
Prospects for further research
Athletes in the snatch, the focus of the movement of the body, physical characteristics of the various sectors of the movement, muscle strength characteristics of barbell trajectory of the movement have a certain impact on technology. This will be the focus of future research. In addition, further study of elite athletes from different countries the technical architecture of the characteristics of action between the same points with different point.
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Came to edition 06.06.2009. wxnsdqsjy@mail.ru
