| Serving is one of the most important skills in tennis sports, each score, each game starts with serving. Serving is also the only ball-driving that is not controlled by rivals in tennis.Serving has always been a killing weapon for outstanding tennis athletes. In a word, serving plays a significant role in tennis. However, serving has always been a weak point for Chinese tennis players especially considering that Chinese male tennis players fall far behind world-level. As such, research into serving is of great significance both theoretically and practically.Up spin serving is characterized as up spin oriented plus a little sidespin. The ball is of morupspin than cutting, which makes an obvious downward arc crossing the net. Spin level is in proportion with the hitting power, the greater the power is, the greater the arc and spin level. The ball will jump highly to the left side of the rival, forcing him to leave his formation, which stress him greatly, and leaves enough time for you. Up spin serving is of great threat to rival and very stable in itself.Serving gestures of samples in test are different; however they have 3 identical moments, which are hitting, the moment the ball ascending to the highest level and the hitting moment. This study focuses on those 3 moments listed. With this study, the author carries out kinematics analysis into the 3 moments, and obtains some important parameters. Meanwhile, with muscle-electricity analysis, this study deeply investigates 10 frames between highest time and hitting point, and conclude the muscle tension to provide theoretical proof for muscle building. This paper studies into 6 excellent tennis players. Combined with literature referencing, expert interview, observation, experiment and statistical study to process selected indexes.Conclusions are as followed based on this study:1:Hitting height should be lower than the height of the player, it's best to keep the hitting height the same as the eyebrow. Average gap between the highest point and hitting point is 0.512m. This data decreased as the level of the player progresses.2:At the highest moment, for the players with up-step position, the angel of their left-should is larger than forward-back position. There will be more discharge as well. So, it's important in particularly for players with up-step position to pay attention to work out their left-sided external oblique.3:The speed of the ball averages at 5.657 m/s when hand moves. This slower the speed is, the more excellent the player is. At the moment ball climbing to the highest point, for players with higher level, their right shoulder and right coax move more quickly, their waist turning movement is more obvious, thus the bigger speed of the ball is.4:The average IEMG (from big to small) as below:right trapezius> right deltoid> right triceps brachii> right brachioradialis>right quadriceps femoris>left gluteus maximus> right external oblique>right biceps femoris. The IEMG level of right trapezius is the largest, which means the highest discharging level goes to the right trapezius, which also actions for the longest duration. And, the EMG evel for right deltoid, right triceps brachii, right brachioradialis and right quadriceps femoris is also remarkable. Worthy mentioning that players with higher level tender to discharge more in their 3 below muscles. So, it's recommended that we pay more attention to those muscles.5:For the 8 muscles in study, their discharging level changes as below:The moment when the ball,climbs to the highest level, brachioradialis,trapezius and deltoid are the major functioning muscles; 10 frames after the racket hits the ball, the discharging level of all 7 muscles decreases expect for the left gluteus maximus. This phenomenon is more obvious in players with better level. Systematical track and field sports help tennis player's control of the muscle, which will synergize and improve their serving level.6:8 muscle discharge the order for right trapeziusâ†'right deltoidâ†'right brachioradialisâ†'right quadricepsâ†'ight biceps femorisâ†'left gluteus maximusâ†'right triceps brachiiâ†'right external oblique. The analysis of sequences of muscle discharging is intended to provide a theoretical foundation which could assist... |
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