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Applied Mechanics and Materials Vol. 340 (2013) pp 13-16 Online available since 2013/Jul/15 at www.scientific.net © (2013) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMM.340.13 Mechanical Analysis on Tennis Forehand Drive Xuhui Zhang Sports Department, Harbin Physical Education Institute, 150008, Harbin, China e-mail: [email protected] Keywords: Coupling Tennis, Forehand Drive, Mechanical Analysis Abstract At present, more and more tennis players use forehand drive play to carry out important tennis match in the tennis sports. In order to better tennis forehand pumping ball to understand technical motion analysis, the use of tennis forehand drive action to carry on mechanical analysis. Through the theoretical mechanics analysis of tennis forehand drive, to select our country excellent tennis players carry out tennis forehand drive experimental mechanical analysis, at the same time, tennis players use the forehand drive movement structure and the comprehensive effect of smoke ball for the different rotation tennis of forehand out, which can obtain the mechanics characteristic of tennis athletes forehand drive technology movement that conduce to tennis players' attack and defence skill training. Introduction With the rapid development of the tennis sport, it has become the second largest sports project; its unique characteristics become important sports events in modern sports activities. At the some time, with the development of modern science technology, especially the development of new materials and applications, to vigorously promote the development of sports. On the rapid development of tennis sport, it has formed a variety of play tennis of different styles, and also has obtained not small result, however various tennis styles require a different technical action to support [1-2]. The development of modern science technology makes the tennis movement vigorously reform from tennis racket materials to quality assurance, to change the past racket’s sport properties, making modern tennis racket is more aggressive, but also increases the play of tennis players. Namely, tennis players can pitch high speed rotating ball in the bottom line, and enhances tennis offensive, especially tennis forehand topspin or drive has become a important offensive means of tennis player, therefore, the mechanical analysis of tennis athletes forehand drives and the stress characteristics of different direction ball, tennis players can get further understanding [3-4]. Mechanics Analysis of Forehand Smash and Tennis Contact Racket First of all, the tennis racket makes assumptions: racket quality is M the stress is a constant force as F , having certain acceleration is a ; at T1 moment, the tennis speed is V1 ; at T2 moment, the tennis speed is V2 ; acting on the tennis racket’s force duration is ∆T , to get [5]: F ∆T = MV2 − MV1 (1) Usually, in the forward swing the tennis racket motion process, to provide external force for the tennis racket is not constant that is constantly changing, so it can be seen [6]: T2 ∫ F (T )dT = MV 2 − MV1 (2) According to momentum conservation laws in the mechanics, it can be seen that Tennis racket T1 sufferer’s sport impulse is ∫ T2 F (T )dT in formula (1) and formula (2), and tennis racket’s the change of momentum is ( ). Generally, tennis athletes will self-control tennis speed during the stroke, which requires tennis player to give tennis a huge momentum, then to transfer tennis racket momentum to tennis in exercise. Therefore, in order to achieve rapid tennis speed, it needs to be given a tennis racket huge momentum to achieve the speed of the tennis before tennis player hits ball [7-8]. T1 MV2 − MV1 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 165.215.209.15, ProQuest-16/10/13,02:36:54) 14 Green Manufacturing, Mechanical and Automation Engineering At the same time, in the process of tennis, tennis players usually use forehand shot that has a rotating characteristics, namely rotating ball. However, the rotating ball is also divided into topspin and backspin. Therefore, when tennis player hits the ball, we need to observe the force circumstances of tennis racket as shown in Fig. 1. In Fig. 1, it can be seen that tennis in the moment of contacting with racket subjects three directions of force: the first is its own weight G ; the second is a tennis racket to give tennis momentum that is the supporting force F ; the third is the friction of tennis subject racket f , however θ is batting directions angle. Generally, through the tennis forehand, it will be rebound by the court surface, so the topspin velocity is greater than the speed of topspin tennis; this is due to the rotating tennis that contacts with ground, the ground will give tennis a level of movement impulse, making the tennis to subject the increments of the horizontal direction velocity ∆V . Fig. 1 Mechanical analysis of topspin (Left) and backspin (right) Assumptions tennis contact with stadium ground’s bounce rate is V1 , it can get topspin speed and backspin speed of tennis [9-10]: VTopspin x = V1 sin θ + ∆V (3) VBackspin x = V1 sin θ − ∆V (4) In formula (3) and formula (4), it can be seen that the tennis players play on the topspin speed that is faster than the backspin after tennis rebound [11]. Research Object and Method Research Object Our young tennis players A and B are as research objects, they are all being hand vigorously out topspin as the main play’s tennis players. The basic situation of two athletes is shown in Table 1 Table 1 Basic situation statistical tables of two athletes A B Birth date 1988 1989 Height(m) Weight(kg) 1.84 1.85 73 73 Training time(Year) 10 8 Technique Right-hand Right-hand Research Method Using a questionnaire survey method with the tennis sports industry’s experts, coaches and athletes to discuss the tennis technology movement, in view of our country tennis athletes to carry on tennis serve and forehand smash, and to carry on the research on attack technology and other aspects. Using the scene coach evaluation method to carry on comprehensive evaluation for tennis player’s tennis smash action and tennis sport effect, the smash action of tennis players are divided into three categories: failing, general as well as excellent. A round of tennis players has 10 times, it needs to complete 2 round. Experimental Equipment Using the experimental equipment mainly has recorder, tripod, and geodetic coordinate frame and so on. The use of computer carries out data processing and image analysis of tennis forehand drive. 14 Green Manufacturing, Mechanical and Automation Engineering At the same time, in the process of tennis, tennis players usually use forehand shot that has a rotating characteristics, namely rotating ball. However, the rotating ball is also divided into topspin and backspin. Therefore, when tennis player hits the ball, we need to observe the force circumstances of tennis racket as shown in Fig. 1. In Fig. 1, it can be seen that tennis in the moment of contacting with racket subjects three directions of force: the first is its own weight G ; the second is a tennis racket to give tennis momentum that is the supporting force F ; the third is the friction of tennis subject racket f , however θ is batting directions angle. Generally, through the tennis forehand, it will be rebound by the court surface, so the topspin velocity is greater than the speed of topspin tennis; this is due to the rotating tennis that contacts with ground, the ground will give tennis a level of movement impulse, making the tennis to subject the increments of the horizontal direction velocity ∆V . Fig. 1 Mechanical analysis of topspin (Left) and backspin (right) Assumptions tennis contact with stadium ground’s bounce rate is V1 , it can get topspin speed and backspin speed of tennis [9-10]: VTopspin x = V1 sin θ + ∆V (3) VBackspin x = V1 sin θ − ∆V (4) In formula (3) and formula (4), it can be seen that the tennis players play on the topspin speed that is faster than the backspin after tennis rebound [11]. Research Object and Method Research Object Our young tennis players A and B are as research objects, they are all being hand vigorously out topspin as the main play’s tennis players. The basic situation of two athletes is shown in Table 1 Table 1 Basic situation statistical tables of two athletes A B Birth date 1988 1989 Height(m) Weight(kg) 1.84 1.85 73 73 Training time(Year) 10 8 Technique Right-hand Right-hand Research Method Using a questionnaire survey method with the tennis sports industry’s experts, coaches and athletes to discuss the tennis technology movement, in view of our country tennis athletes to carry on tennis serve and forehand smash, and to carry on the research on attack technology and other aspects. Using the scene coach evaluation method to carry on comprehensive evaluation for tennis player’s tennis smash action and tennis sport effect, the smash action of tennis players are divided into three categories: failing, general as well as excellent. A round of tennis players has 10 times, it needs to complete 2 round. Experimental Equipment Using the experimental equipment mainly has recorder, tripod, and geodetic coordinate frame and so on. The use of computer carries out data processing and image analysis of tennis forehand drive. Applied Mechanics and Materials Vol. 340 15 Fig. 2 Experimental venue and equipment location map Analysis of Tennis Forehand Drive Mechanical Experiment According to the experiment on tennis forehand drive mechanics analysis: Analysis of Tennis Player’s Backswing Process In the forehand drive process, shoulder angle and dead angle can reflect the tennis athlete in the whole amplitude of backward traction tennis racket. Its experimental results can be shown in Table 2. Table 2 Body mechanics parameters during the two tennis player’s backswing A B Knee angle 121.7 117.3 Elbow angle 138.2 133.4 Shoulder angle 42.6 45.2 Hip angle 82.0 89.2 Wrist angle 53.6 73.6 Fig. 3 Body mechanics angle change chart during two tennis player’s backswing From Table 2 and Fig. 3, they can be shown that the shoulder angle is 25.2 at the end of racket, A is 12.2; the two tennis’s mechanical angle difference of in the process of racket is quite big. At the same time, the amplitude of two tennis players in swing tennis racket is relatively smaller, which has the forehand drive technical movement characteristics in modern tennis movement Analysis of Tennis Mechanical Speed Parameter during Tennis Player Back Beat The experimental data can be shown in Table 3. Table 3 Mechanical speed parameter table of two tennis players after backswing A B Knee 2.78 0.98 Elbow 1.02 0.87 Shoulder 0.8 0.63 Hip 1.23 0.41 Focus 2.53 0.72 Wrist 1.12 0.96 Fig. 4 Mechanical speed change chart of two tennis players after backswing From Table 3 and Fig. 4, they can be shown that two tennis players after backswing. Forehand drive force line speed of athlete A is greater than athlete B in the process of backward traction tennis racket. Through the analysis, mainly due to the physical coordination of tennis player A , the 16 Green Manufacturing, Mechanical and Automation Engineering forehand drive tends to arc, and the line speed of right hand is relatively constant. However, the gravity line speed tends to below; the smash mechanical movement speed is obviously increased after integrated overlay. The Mechanics Parameters Analysis of Tennis Forehand Drive Rotary Angle The experimental data can be shown in Table 4. Table 4 Mechanical angle change time parameter table of tennis forehand drive rotary A B Tennis angle 21.78 14.98 Tennis racket angle 35.02 43.87 Court surface angle 62.8 61.63 Fig. 5 Mechanical angle change parameter chart of tennis forehand drive rotary In Fig. 5, it can be seen that the forehand drive amplitude angle of two tennis players are close. On the moment of tennis racquet and tennis contact, B has a certain angle advantages, and has certain beneficial effects for the hitting force. Conclusion The experimental results show that the mechanical factors and the effects of influence the tennis player forehand have a lot, however a mechanical perspective analysis shows that the different spin tennis need a reasonable of forehand drive angle and tennis players’ various parts of the body joint velocity with superimposed, and then it should be adjusted to various parts of the mechanical line speed. In the process of increasing forehand drive, the driving force of tennis player should increase the racket tennis way and physical development, and keep the body follow up speed, the forehand drive effect will be more obvious. The experimental results show that tennis players carry out forehand drive training and deal with opponents to provide a scientific basis in the race. References [1] Hu. Q. Q. (2009) Biomechanical analysis of Chinese elite young tennis players powerful forehand topspin Beijing Sport University 1(8):112-116 [2] Ma. W. (2009) Experimental study of quick power on tennis forehand hitting speed influence Liaoning normal university 2(3):122-124 [3] Pan. S. (2009) Comparison of two tennis ground strokes technology characteristics and its biomechanical characteristics. Journal of Suzhou University (Natural science edition) 3(8):127-129 [4] Liu. H. (2009) Biomechanics principle of tennis service technique Journal of Beijing Sport University 4(3):413-417 [5] Wang. Y. (2010) Analysis of tennis forehand stroke limiting factors Journal of Jilin physical institute 5(5):355-358 [6] Guo. J. (2009) Analysis of tennis forehand stroke biomechanical and evaluation Bulletin of sport science 6(12):537-539 [7] Wang. K. J. (2009) Research on modern tennis forehand drives technology teaching. Journal of sports adult education 7(1):743-745 Green Manufacturing, Mechanical and Automation Engineering 10.4028/www.scientific.net/AMM.340 Mechanical Analysis on Tennis Forehand Drive 10.4028/www.scientific.net/AMM.340.13