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1.
Effect of skill decomposition on racket and ball kinematics of the elite junior tennis serve 总被引:1,自引:0,他引:1
Reid M Whiteside D Elliott B 《Sports biomechanics / International Society of Biomechanics in Sports》2010,9(4):296-303
Whole body kinematics of the tennis serve have been reported extensively in the literature, yet comparatively less information exists regarding the kinematic characteristics of the swing and toss. In attempting to develop consistency in placement of the toss and racket trajectory, coaches will often decompose the serve and practice it in separate parts. A 22-camera VICON MX motion analysis system, operating at 250 Hz, captured racket, ball and hand kinematics of the serves of five elite junior players under three conditions. The conditions were flat first serves (FS) directed to a 1 x 1 m target bordering the 'T' of the deuce service box, a ball toss (BT) in isolation and a free swing (SW) in isolation. Players were instructed to perform BT and SW as in the FS. Paired t-tests assessed within-group differences in hand, racket and ball kinematics between the discrete skill and the two decomposed conditions. Vertical displacement of the ball at its zenith increased significantly during BT compared with the FS and temporal associations between racket and ball motion during the FS (r = 0.861) were affected during task decomposition. This study questions the pervasive use of task decomposition in the development of the tennis serve. 相似文献
2.
The purpose of this article was to examine the effect of equipment scaling, through the modification of tennis ball compression, on elite junior tennis players (aged 10 years) within a match-play context. The two types of ball compressions that were compared were the standard compression (the normal ball) and 75% compression (termed the modified ball). Ten boys and 10 girls participated in the study. Participants were stratified into pairs based on their Australian Age Ranking and gender. Each pair played two two-set matches: one match with standard compression balls and one match with modified balls. The characteristics of each match were analysed and compared. The results showed that the use of the modified ball increased rally speed, allowed players to strike the ball at a lower (more comfortable) height on their groundstrokes and increased the number of balls played at the net. Ball compression had no effect on the relative number of winners, forehands, backhands, first serves in and double faults. The results are discussed in relation to skill acquisition for skilled junior tennis players. 相似文献
3.
Measurements are presented of the friction force acting on a tennis ball incident obliquely on the strings of a tennis racket.
This information, when combined with measurements of ball speed and spin, reveals details of the bounce process that have
not previously been observed and also provides the first measurements of the coefficient of sliding friction between a tennis
ball and the strings of a tennis racket. At angles of incidence less than about 40° to the string plane, the ball slides across
the strings during the whole bounce period. More commonly, the ball is incident at larger angles in which case the ball slides
across the string plane for a short distance before gripping the strings. While the bottom of the ball remains at rest on
the strings, the remainder of the ball continues to rotate for a short period, after which the ball suddenly releases its
grip and the bottom of the ball slides backwards on the string plane. The bounce angle depends mainly on the angle of incidence
and the rotation speed of the incident ball. Differences in bounce angle and spin off head-clamped and hand-held rackets are
also described. 相似文献
4.
网球步法移动对技术掌握的影响分析 总被引:9,自引:2,他引:9
彭国雄 《武汉体育学院学报》2002,36(4):79-81
采用实验对比的方法,探讨步法移动对网球选修班学生掌握各项技术及在不同层次上的影响,结果表明,步法是影响网球技术学习的重要因素,加强步法的学习是掌握技术的重要前提。 相似文献
5.
直拍横打技术对广东高校乒乓球教学的启示 总被引:1,自引:0,他引:1
通过对第49届世界乒乓球锦标赛团体赛马琳对柳承敏的录像分析,发现双方均是直拍快攻型选手,而马琳反手是推挡加横打型,柳承敏反手是推挡加攻球型,马琳的直拍横打优于柳承敏的反手推挡,直拍横打解决了直拍运动员反手攻击力不强的问题,直拍近台快攻打法有强大的生命力。结合广东部分高校体育专业乒乓球班学生与普通系乒乓球班学生的现状进行分析,访谈了广东高校一些乒乓球教师,结果表明,广东高校乒乓球直拍横打的发展比较滞后,应该在乒乓球教学中采取措施开展直拍横打,方能使乒乓球的群众性运动进一步发展。 相似文献
6.
Serving to different locations: set-up, toss, and racket kinematics of the professional tennis serve
Reid M Whiteside D Elliott B 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):407-414
The serve, as the most important stroke in tennis, has attracted considerable biomechanical interest. Of its component parts, the swing has received disproportionate research attention and consequently, little is known regarding toss kinematics. Indeed, the age-old question of whether players serve to different parts of the court from the same toss remains unanswered. Six right-handed professionally ranked players hit first serves (FSs) and second serves (SSs) to three 2 x 1 m target areas reflecting the landing locations of T, body and wide serves, respectively, on the deuce court. A 22 camera, 250 Hz VICON MX motion analysis system captured racket, ball, foot, and h and kinematics. Repeated measures ANOVAs assessed within-player differences in foot, racket, and ball kinematics within the FS and SS as a function of landing location. The positions of the front foot, ball zenith, and ball impact were significantly different in the FS, while kinematics across all SS were consistent. Front foot position was closer to the centre mark in the T FS and players impacted the ball further left in the wide FS compared to the T FS. This study discusses the findings in the context of the development of the serve as well as potential implications for the return. 相似文献
7.
探析网球运动在中国快速发展的原因 总被引:14,自引:0,他引:14
对网球运动在中国快速发展的原因进行了探讨。认为网球运动的健身娱乐性、在世界上的影响力、高雅时尚、可作为有效的社交媒介等特点符合中国人日益增长的对体育更高层次的需求。经济的发展和收入的增加是网球运动普及的保证。提出只有认真学习并掌握网球运动的特点和发展规律,并使之与人们对体育运动的需求相结合,才能推动中国网球运动的健康发展。 相似文献
8.
Alexander Nicolaides Nathan Elliott John Kelley Mauro Pinaffo Tom Allen 《Sports Engineering》2013,16(3):181-188
Topspin has become a vital component of modern day tennis. Ball-to-string bed and inter-string friction coefficients can affect topspin generation from a racket. The aim of this research was to determine the effect of string bed pattern on topspin generation. Tennis balls were projected onto nine head-clamped rackets with different string bed patterns. The balls were fired at 24 m/s, at an angle of 26° to the string bed normal with a backspin rate of 218 rad/s and outbound velocity, spin and angle were measured. Outbound velocity was shown to be independent of string bed pattern. Outbound angle increased with the number of cross strings, while outbound topspin decreased. In the most extreme case, decreasing the number of cross strings from 19 to 13 increased rebound topspin from 117 to 170 rad/s. 相似文献
9.
Three‐dimensional (3‐D) high‐speed cinematographic techniques were used to record topspin and backspin forehand approach shots hit down‐the‐line by high‐performance players. The direct linear transformation (DLT) technique was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. A Mann‐Whitney U‐test was calculated for the different aspects of the topspin and backspin shots to test for significance (P<0.05). A significant difference was recorded between topspin and backspin shots in the angle of the racket at the completion of the backswing. The racket was taken 0.48 rad past a line drawn perpendicular to the back fence for topspin trials, but only rotated 0.86 rad from a line parallel to the net in the backspin shot. Maximum racket velocities occurred prior to impact and were significantly higher in topspin (26.5 m s‐1) compared to backspin (16.6 m s‐1) trials. This resulted in the topspin trials recording a significantly higher ball velocity compared to backspin trials (27.6 m s‐1 vs 21.7 m s‐1). Pre‐impact racket trajectories revealed that in topspin shots the racket moved on an upward path of 0.48 rad while in backspin shots it moved down at an angle of 0.34 rad. In the topspin trials impact occurred significantly further forward of the front foot than in backspin shots (0.26 m vs 0.05 m) while the angle of the racket was the same for both strokes (0.14 rad behind a line parallel to the net). The mean angle of the racket‐face at impact was inclined backwards by 0.11 rad for backspin strokes and rotated forward by 0.13 rad for topspin strokes. Angles of incidence and reflection of the impact between the ball and the court showed that backspin trials had larger angles of incidence and reflection than topspin strokes. 相似文献
10.
Eighteen elite male tennis players were tested to determine their ability to identify string tension differences between rackets
strung from 210 N (47 lb) to 285 N (64 lb). Each player impacted four tennis balls projected from a ball machine before changing
rackets and repeating the test. Eleven participants (61%) could not correctly detect a 75 N (17 lb) difference between rackets.
Only two participants (11%) could correctly detect a 25 N (6 lb) difference. To establish whether varying string tensions
affected ball rebound dynamics, the ball’s rebound speed and landing position were analysed. The mean rebound ball speed was
117 km h−1, with only the trials from the 210 N racket producing significantly lower (P < 0.05) rebound speeds than the 235 N and 260 N rackets. This is contrary to previous laboratory-based tests where higher
rebound speeds are typically associated with low-string tensions. The anomaly may be attributable to lower swing speeds from
participants as they were not familiar with such a low string tension. Ball placement did not appear related to string tension,
with the exception of more long errors for the 235 N racket and fewer long errors for the 285 N racket. It was concluded that
elite male tennis players display limited ability to detect changes in string tension, impact the ball approximately 6% faster
than advanced recreational tennis players during a typical rallying stroke, and that ball placement is predominantly unrelated
to string tension for elite performers. 相似文献
11.
张继科右2/3台反手侧拧接发球技术效果研究 总被引:1,自引:0,他引:1
运用文献资料法、录像观察统计法,对优秀乒乓球运动员张继科右2/3台反手接发球的效果进行研究,旨在为丰富接发球的方法与手段提供参考。结果认为:张继科在右2/3台范围内运用反手侧拧接发球比运用正手抢拉有更高的稳定性,而且比运用正手抢拉接发球更容易直接得分。不但丰富了此范围内接发球的方式,而且增加了比赛中接发球的突然性,为比赛赢得主动。 相似文献
12.
13.
Comparing the pre- and post-impact ball and racquet kinematics of elite tennis players' first and second serves: a preliminary study 总被引:1,自引:0,他引:1
Chow JW Carlton LG Lim YT Chae WS Shim JH Kuenster AF Kokubun K 《Journal of sports sciences》2003,21(7):529-537
The aim of this study was to compare the pre- and post-impact three-dimensional kinematics of the ball and racquet during first and second serves performed by elite tennis players. Data were collected from four male and four female right-handed professional players during competition using two high-speed cameras (200 Hz). For each player, one first serve and one second serve from the 'deuce' or right service court that landed within the specified target area were analysed. To test for significant differences between the first and second serves, Wilcoxon tests (P < or = 0.05) were performed on selected parameters. The results indicate that the ball travelled forward and to the left during the flight phase of the toss in all but one trial. The average pre-impact ball forward location for the first serve was significantly more in front and had a higher associated forward ball velocity than the corresponding values for the second serve. On average, the decrease in post-impact ball speed from the first to the second serve was 24.1%. No significant differences between the first and second serves were found in the pre-impact racquet head speed and orientation, which was represented as a unit vector perpendicular to the racquet face. The major adjustments made by the players when going from the first to second serve were a decrease in pre-impact ball forward location (P < or = 0.01) and an increase in the pre-impact racquet vertical and lateral velocities (both P < or = 0.05). This implies that the players tossed the ball closer to the body and imparted topspin and sidespin on the ball by changing the racquet vertical and lateral velocities when going from the first to the second serve. 相似文献
14.
大学生网球运动损伤的调查研究 总被引:19,自引:0,他引:19
对从事网球运动的学生运动损伤的特征、部位、种类,以及损伤原因进行了调查。结果发现,大学生网球运动损伤多以关节扭伤为主,集中在人体的腕、肘、肩及踝关节。损伤的主要原因是技术动作错误和局部负担过重,同时提出了预防网球运动损伤的措施和建议。 相似文献
15.
Alexandros Mavidis Efstratios Vamvakoudis Thomas Metaxas Panagiotis Stefanidis Nikolaos Koutlianos Kosmas Christoulas 《Journal of sports sciences》2013,31(13):1501-1506
Abstract The aim of this study was to examine the deltoid muscle properties of the dominant and non-dominant arm of Greek professional male tennis players. Eight male tennis players (mean age 22.0 years, s = 3.2) were subjected to biopsy of the deltoid muscle of both arms. Adenosine triphosphate (ATPase) histochemistry and myosin heavy chain (MHC) composition were performed on the samples with homogenate electrophoresis. No significant differences were observed in the percentage of types I, IIa, IIab, and IIb muscle fibres between the deltoid muscles of the two arms. Types I, IIa, and IIx muscle fibres of the dominant and non-dominant deltoid muscles did not differ significantly for MHC isoform composition. Type IIab muscle fibres showed a similar cross-sectional area (CSA) percentage distribution between the two arms. The CSA percentage for types I, IIa, and IIb muscle fibers did not differ significantly between the dominant and the non-dominant arm. We conclude therefore that regular tennis training probably does not lead to any significant changes in the muscle fibre types of the dominant and non-dominant arms of elite tennis players. 相似文献
16.
Blackwell J Knudson D 《Sports biomechanics / International Society of Biomechanics in Sports》2002,1(2):187-192
This study investigated the effect of the larger diameter (Type 3) tennis ball on performance and muscle activation in the serve. Sixteen male advanced tennis players performed serves using regular size and Type 3 tennis balls. Ball speed, surface electromyography, and serve accuracy were measured. There were no significant differences in mean initial serve speeds between balls, but accuracy was significantly greater (19.3%) with the Type 3 ball than with the regular ball. A consistent temporal sequence of muscle activation and significant differences in mean activation of different muscles were observed. However, ball type had no effect on mean arm muscle activation. These data, combined with a previous study, suggest that play with the larger ball is not likely to increase the risk of overuse injury, but serving accuracy may increase compared to play with the regular ball. 相似文献
17.
An explicit finite-element (FE) model of a pressurised tennis ball is presented. The FE model was used to model an oblique
impact between a tennis ball and a rigid tennis surface, to further the understanding of this impact. Impacts were also conducted
in the laboratory and the results from the FE model were in good agreement with this experimental data. The FE model was used
to illustrate why a tennis ball rebounds with a higher vertical coefficient of restitution in an oblique impact compared to
an equivalent impact perpendicular to the surface; this equivalent perpendicular impact has the same inbound velocity as the
vertical component of the oblique impact. The FE model was also used to illustrate that the structural compliance of the felt
covering on a tennis ball was a contributing factor to the ball attaining more spin in the impact than would have been calculated
using a conventional analytical model. Also, the spin values calculated in the FE simulation were in good agreement with experimental
data. 相似文献
18.
The primary aim of this study was to determine whether variations in rebound speed and accuracy of a tennis ball could be detected during game-simulated conditions when using three rackets strung with three string tensions. Tennis balls were projected from a ball machine towards participants who attempted to stroke the ball cross-court into the opposing singles court. The rebound speed of each impact was measured using a radar gun located behind the baseline of the court. An observer also recorded the number of balls landing in, long, wide and in the net. It was found that rebound speeds for males (110.1?±?10.2?km?·?h?1; mean?±?s) were slightly higher than those of females (103.6?±?8.6?km?·?h?1; P?<?0.05) and that low string tensions (180?N) produced greater rebound speeds (108.1?±?9.9?km?·?h?1) than high string tensions (280?N, 105.3?±?9.6?km?·?h?1; P?<?0.05). This finding is in line with laboratory results and theoretical predictions of other researchers. With respect to accuracy, the type of error made was significantly influenced by the string tension (P?<?0.05). This was particularly evident when considering whether the ball travelled long or landed in the net. High string tension was more likely to result in a net error, whereas low string tension was more likely to result in the ball travelling long. It was concluded that both gender and the string tension influence the speed and accuracy of the tennis ball. 相似文献
19.
目的:旨在考察表象能力如何影响网球中运动表象训练后的运动能力提高。方法:将熟练的网球运动员按照他们的运动表象问卷(MIQ)得分被分为三组(强表象组、弱表象组、对照组)。在前测中,被试者对特定的目标接十五个发球。在十五个回合中,身体训练中穿插了运动表象训练。每个回合都由两组实验构成,十五个想象性实验和十五个身体的实验。一部分被试者被要求使用内部视觉表象(强表象组和弱表象组)。而另一些被试者则接受了阅读任务(控制组)。结果:被试者们在48小时后,接受了一项与前测相似的后测。结果显示,运动表象训练提高了接发球的能力,而这种提高在强表象者身上比在弱表象者身上的效果更加明显。 相似文献
20.
运用文献综述、观察及逻辑分析等方法,对隔网持拍类运动的项目特征和能量代谢特征进行分析,同时提出营养补充建议,旨在为隔网持拍项目运动员训练、竞赛及恢复过程提供帮助。 相似文献