共查询到19条相似文献，搜索用时 406 毫秒
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邹云明 《体育科技文献通报》2013,21(1):129-132
随着网球运动在中国的发展,越来越多的人开始从事网球运动,不管是竞技运动还是大众运动,网球拍是每个网球运动员必不可少的装备,如果说把网球运动员比作是一个即将上战场的武士,那么网球拍就是网球运动员手里的武器,武器的好坏直接关系着战局的成败,网球拍在比赛中的作用尤为重要.本文主要运用文献资料法、对比演绎法对网球拍的发展及其演变过程进行了总结,分析了网球拍在各个时代的变化及其未来的发展趋势,为不同水平的网球选手选择拍子和使用拍子提供一定的参考,也让所有的网球运动爱好者更好的了解网球运动文化. 相似文献
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本研究建立了人体上、下肢打击中心的数学模型,并推算了相应的计算公式.基于人体惯性参数,分析了上、下肢鞭打的2个案例,得出当肘关节或膝关节约呈130°角屈曲时,其打击中心恰在腕关节或踝关节处. 相似文献
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《体育健康知识画刊》2009,(9):54-55
也许您是网球初学者．正在为不知如何选购自己的第一支网球拍而发愁．又或者您是有一定基础的中高级玩家，希望对自己的网球拍进行升级您想要更多力量，更多控制．更多舒适，又或者三者都有一些……不论您购买网球拍的原因是什么，您在面对数量多得让人眼花缭乱的网球拍时也许都有一点点无所适从．不知如何挑选适合自己的球拍。 相似文献
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南通 长三角的“甜区” 总被引：1，自引：0，他引：1
在长江入海口的北岸,有一座与上海一衣带水、隔江相望的城市南通,它处于沿海经济带与长江经济带 T 型结构交汇点和长江三角洲洲头,"据江海之会、扼南北之喉",恰如网球拍的"甜区"位置。这座始建于公元958年的城市(古称"通州",后为与北方"通州"区分,更名"南通")既古老又年轻,受洋派文化影响,早在93年前(1915年)便建成了第一片网球场,如今这座中型城市更是拥有近60片网球场,网球人口1000多人,其网球氛围之浓烈让人惊叹。 相似文献
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衡山路上海国际网球中心的室内场里,大屏幕上滚动播放着费德勒在温网夺冠的瞬间,吸引着三三两两的人们驻足,小声议论。今天的主角并不是费德勒,但如果没有今天的主角或许也没有今天的费德勒。环顾四周,很容易地就发现了主角——号称费德勒“延长了的手臂”——他手上的那把网球拍。 相似文献
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选择网球拍,首先要对球拍有一些了解,其次还要考虑自身的打法、特长和身体状态。网球拍是一种高科技产品、对制作材料和工艺都有一定的要求。现在绝大部分网球拍是以重量轻、硬度高的碳纤维为主要原料,“海德”、“王子”和“斯伯丁”产品中还有一部分加入了一种称为“克拉夫”(KEVLAR)的特殊材料,它是制造防弹衣的材料之一,对球拍强度和减震部可起到显著作用。此外“海德”最新产品“金字塔动力”强调拍框和拍柄设计,以金字塔形式设计拍框增加了强度,独特的8个避震器拍柄有效减轻震动;“王子”网拍则运用长粒硅胶加强对网线的固定,“王子”网拍则运用长粒硅胶加强对网线的固定,让震动不易传递到拍框上。网球拍从外观大体可分为标准形和犁形(水滴形)。标准形又有拍面大小和拍柄 相似文献
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在乒乓球运动员发力击球时,以拍面的哪个部位最好?经过测试和研究,认为不是拍子的重心,也不是拍面的中心,而是拍子的“打击中心”。球拍“三心”位置存在显著差异。用“打击中心”部位发力击球,符合力学原理。 相似文献
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Roger J. Missavage John A. W. Baker Carol A. Putnam 《Research quarterly for exercise and sport》2013,84(3):254-260
Abstract This study was undertaken to establish theoretical bases for the experimental results reported by Baker and Putnam (1979), and Walanabe, Ikegami and Miyashita (1979), concerning grip firmness on a tennis racket and its effect on the ratio of post- to pre-impact ball velocity. The model predicted that, for central impacts, there was no change in the ball velocity ratio when a regular tennis racket was tightly clamped at the grip or allowed to freely stand on its butt. To validate the model further, alterations were made to two parameters of the racket—a tennis racket was modified to increase the stiffness, and a racketball racket was used to simulate a shortened tennis racket. Multiple exposure photographs were taken of balls striking the center of the rackets under the two extremes of grip firmness. Measurements were taken from enlargements of these photographs in order to calculate the horizontal component of post- to pre-impact ball velocity. It was found that shortening the length and greatly increasing the stiffness was required before the effect of grip firmness was noticeable. 相似文献
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Abstract Stroboscope photography and accelerometry techniques were used to measure rebound velocities of tennis balls from impact locations on the strings and vibration levels at the rotation point on the racket handle for both conventional and oversized tennis rackets. The oversized rackets demonstrated lower vibration levels and higher rebound velocities than their conventional counterparts when balls struck by the racket were compared along a transverse axis drawn perpendicular to the racket shaft and through the geometric center of the strings. These differences were, however, only significantly different (p < .01) at the impact location 6 cm along this axis toward the top edge of the racket. Higher rebound velocities were recorded at all impact points from the oversized rackets along the axis in line with the racket shaft. Significantly lower vibration levels were apparent at locations 4 cm, 6 cm, and 8 cm from the string center away from the racket handle. The lower vibration levels, particularly at the extremes of the racket face, in conjunction with higher rebound velocities, support the concept that this new racket design is of practical benefit to users. 相似文献
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Bruce Elliott 《Research quarterly for exercise and sport》2013,84(4):277-281
Abstract The effects of string tension and longitudinal racket flexibility on post-impact ball velocity were investigated in tennis. Six wooden rackets, two with flexible shafts, two with medium and two with stiff shafts were strung with synthetic gut at tensions of 245N (55 lb), 289N (65 lb) and 334N (75 lb). A pneumatically driven racket-arm was triggered by a stimulus from a photo-electric cell positioned at the exit nozzle of a ball machine so that impact occurred with the racket perpendicular to the path of the ball. New tennis balls were fired to impact each racket at the geometric center of the strings and 5 cm above the geometric center. The average horizontal velocity of the ball, both before and after impact, was determined using stroboscope photography. A significant interaction between racket stiffness and string tension was recorded for an inward ball velocity of 22.7 m/s and a racket velocity of approximately 6.8 m/s. String tension had no significant influence on rebound velocity for a stiff racket following impact with a moving racket. Medium and flexible rackets produced the highest coefficients of restitution when strung at 245N (55 lb) compared to 289N (65 lb) and 334N (75 lb). 相似文献
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The application of advanced engineering to tennis racket design has influenced the nature of the sport. As a result, the International Tennis Federation has established rules to limit performance, with the aim of protecting the nature of the game. This paper illustrates how changes to the racket affect the player-racket system. The review integrates engineering and biomechanical issues related to tennis racket performance, covering the biomechanical characteristics of tennis strokes, tennis racket performance, the effect of racket parameters on ball rebound and biomechanical interactions. Racket properties influence the rebound of the ball. Ball rebound speed increases with frame stiffness and as string tension decreases. Reducing inter-string contacting forces increases rebound topspin. Historical trends and predictive modelling indicate swingweights of around 0.030–0.035 kg/m2 are best for high ball speed and accuracy. To fully understand the effect of their design changes, engineers should use impact conditions in their experiments, or models, which reflect those of actual tennis strokes. Sports engineers, therefore, benefit from working closely with biomechanists to ensure realistic impact conditions. 相似文献
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Recreational tennis players tend to have higher incidence of tennis elbow, and this has been hypothesised to be related to one-handed backhand technique and off-centre ball impacts on the racket face. This study aimed to investigate for a range of participants the effect of off-longitudinal axis and off-lateral axis ball–racket impact locations on racket and forearm joint angle changes immediately following impact in one-handed tennis backhand groundstrokes. Three-dimensional racket and wrist angular kinematic data were recorded for 14 university tennis players each performing 30 “flat” one-handed backhand groundstrokes. Off-longitudinal axis ball–racket impact locations explained over 70% of the variation in racket rotation about the longitudinal axis and wrist flexion/extension angles during the 30 ms immediately following impact. Off-lateral axis ball–racket impact locations had a less clear cut influence on racket and forearm rotations. Specifically off-longitudinal impacts below the longitudinal axis forced the wrist into flexion for all participants with there being between 11° and 32° of forced wrist flexion for an off-longitudinal axis impact that was 1 ball diameter away from the midline. This study has confirmed that off-longitudinal impacts below the longitudinal axis contribute to forced wrist flexion and eccentric stretch of the wrist extensors and there can be large differences in the amount of forced wrist flexion from individual to individual and between strokes with different impact locations. 相似文献
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Science and the major racket sports: a review 总被引：1，自引：1，他引：0
Lees A 《Journal of sports sciences》2003,21(9):707-732
The major racket sports include badminton, squash, table tennis and tennis. The growth of sports science and the commercialization of racket sports in recent years have focused attention on improved performance and this has led to a more detailed study and understanding of all aspects of racket sports. The aim here, therefore, is to review recent developments of the application of science to racket sports. The scientific disciplines of sports physiology and nutrition, notational analysis, sports biomechanics, sports medicine, sports engineering, sports psychology and motor skills are briefly considered in turn. It is evident from these reviews that a great deal of scientific endeavour has been applied to racket sports, but this is variable across both the racket sports and the scientific disciplines. A scientific approach has helped to: implement training programmes to improve players' fitness; guide players in nutritional and psychological preparation for play; inform players of the strategy and tactics used by themselves and their opponents; provide insight into the technical performance of skills; understand the effect of equipment on play; and accelerate the recovery from racket-arm injuries. Racket sports have also posed a unique challenge to scientists and have provided vehicles for developing scientific methodology. Racket sports provide a good model for investigating the interplay between aerobic and anaerobic metabolism and the effect of nutrition, heat and fatigue on performance. They have driven the development of mathematical solutions for multi-segment interactions within the racket arm during the performance of shots, which have contributed to our understanding of the mechanisms of both performance and injury. They have provided a unique challenge to sports engineers in relation to equipment performance and interaction with the player. Racket sports have encouraged developments in notational analysis both in terms of analytical procedures and the conceptualization of strategy and tactics. Racket sports have provided a vehicle for investigating fast interceptive actions, hand-eye coordination and perception-action coupling in the field of motor control. In conclusion, science has contributed considerably to our knowledge and understanding of racket sports, and racket sports have contributed to science by providing unique challenges to researchers. 相似文献
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Effect of tennis racket parameters on a simulated groundstroke 总被引：1，自引：0，他引：1
Composite materials have given manufacturers the freedom to develop a broad range of tennis rackets, allowing them to change key parameters such as the structural stiffness, mass, and position of the balance point. The aim of this research was to determine how changing these parameters could affect ball resultant rebound velocity and spin for a simulated groundstroke. A finite element model of a freely suspended racket and strings was used to determine the effect of racket parameters for oblique spinning impacts at a range of locations on the stringbed. The finite element simulations were conducted in the laboratory frame of reference, where the ball is projected onto an initially stationary racket. The mean rebound velocity of the ball was 9% higher for a structurally stiff racket, 37% higher for a heavy racket, and 32% higher for a head-heavy racket. In addition, the mean rebound topspin of the ball was 23% higher for a heavy racket and 21% higher for a head-heavy racket. Therefore, in relation to a groundstroke with an impact location away from the node, the rebound velocity of the ball is likely to increase with the structural stiffness of a racket. The effect of changing the mass and position of the balance point is more complex, as it is dependent on the relationship between the transverse moment of inertia and maximum pre-impact swing velocity. 相似文献
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The purpose of this study was to investigate the effect of the racket mass and the rate of strokes on the kinematics and kinetics of the trunk and the racket arm in the table tennis topspin backhand. Eight male Division I collegiate table tennis players hit topspin backhands against topspin balls projected at 75 balls · min?1 and 35 balls · min?1 using three rackets varying in mass of 153.5, 176 and 201.5 g. A motion capture system was used to obtain trunk and racket arm motion data. The joint torques of the racket arm were determined using inverse dynamics. The racket mass did not significantly affect all the trunk and racket arm kinematics and kinetics examined except for the wrist dorsiflexion torque, which was significantly larger for the large mass racket than for the small mass racket. The racket speed at impact was significantly lower for the high ball frequency than for the low ball frequency. This was probably because pelvis and upper trunk axial rotations tended to be more restricted for the high ball frequency. The result highlights one of the advantages of playing close to the table and making the rally speed fast. 相似文献