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1.
The purpose of this study was to determine the sources of visual information used by highly skilled tennis players in anticipating their opponent's shots. In Experiment 1, motion analysis of the strokes showed that the relative motion between the racquet and forearm was different between the ground strokes and lobs, but there were no reliable kinematic differences when shot direction was varied. In Experiment 2, 12 skilled tennis players observed the opponent hitting strokes in a normal video or in a point-light display with different segments occluded. Players' anticipation accuracy was not degraded by the use of the point-light display. Occluding the racquet and forearm significantly reduced the participant's ability to determine the type of stroke produced.  相似文献   

2.
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   

3.
ABSTRACT

By manipulating the congruency between body kinematics and subsequent ball trajectory, this study investigated the anticipation capabilities of regional-level, college-level, and novice table tennis players using a full video simulation occluder paradigm. Participants watched footage containing congruent, incongruent, or no ball trajectory information, to predict the landing point of the ball. They were required to choose between two potential locations to make their prediction. Percent accuracy and relevant indexes (d-prime, criterion, effect size) were calculated for each condition. Results indicated that experienced table tennis players (both regional and college players) were superior to novices in the ability to anticipate ball trajectory using kinematic information, but no difference was found between regional-level and college-level players. The findings of this study further demonstrate the superior anticipation ability of experienced table tennis players. Furthermore, the present result suggests that there may be a certain “baseline” level of motor experience in racquet sports for effective action anticipation, while the addition of further motor experience does not appear to assist direction anticipation.  相似文献   

4.
文章通过对我国优秀女子网球单打选手与世界优秀女子网球单打选手的比赛录像分析,进一步诊断与评价我国优秀女子网球单打选手的技战术运用特征。结果表明,我国优秀女子网球单打选手的一发成功率较高,得分率较差,发球的攻击性不足;非受迫性失误较高,接发球得分率和破发点较差。发球抢攻技术、接发球抢攻技术以及上网技术的使用率比较低。得分方式有17.8%是靠主动得分,45.3%是靠对手的非受迫性失误得分,36.9%是靠对手的受迫性失误得分;失分的主要方式为非受迫性失误。  相似文献   

5.
The study investigated differences in the one- (SH) and two-handed (DH) backhands when hit flat, across-court (AC) and down-the-line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college-level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high-speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement). Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique. The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1 degrees; DH: 83.4 degrees) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m: DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m: DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s: DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique.  相似文献   

6.
Abstract

Female novice tennis players (N = 42) were randomly assigned to one of three videotape replay (VTR) conditions: Performance Information Feedback (PIF); Environmental Information Feedback (EIF); or a combination of both (PEIF) to ascertain whether the treatments differentially affected open (ground-strokes) and closed (serve) skills. Performance measures were obtained on a pretest and posttest as well as during session 4 and session 8. Cues appropriate to the VTR condition were employed to direct the subjects' attention. Two analyses were conducted: a MANOVA on the pretest/posttest improvement scores and a three factor ANOVA for the session 4/session 8 scores. For the first analysis, follow-up ANOVAs revealed that for forehand and backhand PEIF improved more than either PIF or EIF and that EIF improved more than PIF. For the serve PEIF improved more than PIF and EIF but the latter two were not significantly different. In the three factor ANOVA all main effects were significant: PEIF was better than EIF and both were better than PIF; serve scores were higher than those for groundstrokes; and session 8 scores were higher than those for session 4. In addition, all interactions except that for skill × session were significant. Based on the results it is recommended that in closed skills PEIF or PIF be used but not EIF and in open skills PEIF or EIF be used but not PIF. The results were also discussed with respect to the Gentile (1972)and Schmidt (1975) views on open and closed skills. While there is some support for Gentile's position it was concluded that further research is necessary.  相似文献   

7.
The aim of this study was to determine the match activity and physiological demands of women's tennis during a 3-day clay-court tennis tournament. The activity profile of eight players was determined by filming each competitive match with video cameras. Metabolic-perceptual measurements--blood samples and individual ratings of perceived exertion (RPE)--were taken while the players were sitting during permitted changeover breaks in play. The activity profile of the players was as follows: strokes per rally, 2.5 +/- 1.6; rally duration, 7.2 +/- 5.2 s; rest time between rallies, 15.5 +/- 7.3 s; effective playing time, 21.6 +/- 6.1%; work-to-rest ratio, 1:2.1. Blood lactate concentration [2.2 +/- 0.9 mmol x l(-1) (n = 50) vs. 2.2 +/- 0.7 mmol x l(-1) (n = 48)] and RPE values [12.2 +/- 2.4 (n = 57) vs. 12 +/- 2.3 (n = 57)] were not significantly different (P = 0.65-0.78) between service and return games. The results highlight the importance of taking these factors (i.e. activity patterns and physiological profile) into account when planning training strategies for competitive females players. As such, tennis training regimes should be adapted to the specific demands imposed by match-play in female players on a clay-court surface.  相似文献   

8.
Tennis     
The study investigated differences in the one‐ (SH) and two‐handed (DH) backhands when hit flat, across‐court (AC) and down‐the‐line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college‐level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high‐speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement). Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique. The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1°; DH: 83.4°) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m; DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m; DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s; DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique.  相似文献   

9.
ABSTRACT

Differences and similarities between table tennis and other racquet sports exist, but are not well documented in the literature, in spite of the relevance for talent identification. In this study we aimed at identifying the key characteristics of table tennis in comparison with tennis and badminton based upon a survey in coaches. A total of 177 licensed coaches from all across the world and with diverse professional backgrounds completed a survey on anthropometric measures, physical performance, and motor coordination skills. On a scale from 1 to 10, coaches indicated to what extent a talent characteristic was important for their sport. MANOVA identified key differences as well as similarities between all three racquet sports and a subsequent discriminant analysis allocated coaches correctly for table tennis, tennis, and badminton 81.01%, 55.6%, and 71.4% respectively. Our results show that table tennis and other racquet sport coaches are well aware of differences between the racquet sports and also the importance and value of testing and assortment of skill components. These findings can assist coaches in future talent orientation and transfer in racquet sports.  相似文献   

10.
The purpose of this study was to create a valid and reliable assessment scale for the evaluation of three basic tennis strokes (forehand, backhand, serve) for 6–12-year-old tennis players, named the Tennis Rating Score for Children (TRSC). Altogether 60 players (21: forehand, 22: backhand, 17: serve) were video recorded (30 frames per second) while performing three main tennis strokes and later evaluated using the TRSC by five tennis trainers at Day 1 and Day 7. Agreement between days and raters was examined using the intraclass correlation coefficients (ICC). A Pearson’s correlation was calculated to determine convergent validity (score related to participant’s level of experience). The reliability between raters was very high for all three main strokes (ICCFOREHAND = 0.874; ICCBACKHAND = 0.877; ICCSERVE = 0.877). The intra-rater test-retests ICCs were also very high (ICCFOREHAND = 0.885; ICCBACKHAND = 0.891; ICCSERVE = 0.887). A large (rFOREHAND = 0.660) and very large (rBACKHAND = 0.730; rSERVE = 0.772) Pearson’s correlations were found between all the ratings and the level of experience. The TRSC is shown to be highly reliable and valid when assessing technical skills in novice players, when compared to actual assessment from coaching experts; this tool may be helpful for tennis coaches to make a more objective diagnostic of the technical level of young tennis players.  相似文献   

11.
Abstract

Affordances mean opportunities for action. These affordances are important for sports performance and relevant to the abilities developed by skilled athletes. In racquet sports such as badminton, different players prefer widely different string tension because it is believed to provide opportunities for effective strokes. The current study examined whether badminton players can perceive the affordance of string tension for power strokes and whether the perception of affordance itself changed as a function of skill level. The results showed that string tension constrained the striking performance of both novice and recreational players, but not of expert players. When perceptual capability was assessed, perceptual mode did not affect perception of the optimal string tension. Skilled players successfully perceived the affordance of string tension, but only experts were concerned about saving energy. Our findings demonstrated that perception of the affordance of string tension in badminton was determined by action abilities. Furthermore, experts could adjust the action to maintain a superior level of performance based on the perception of affordance.  相似文献   

12.
In tennis, a high ball velocity and a fast run toward the net are key features to successful performance of "serve-and-volley" players. For the serve, tennis players can use two techniques: the foot-up (FU) or foot-back (FB) technique. The aim of this study was to determine if the running time toward the net after the serve and the ball velocity (V(ball)) vary between these two techniques. Moreover we analysed the angular momentum values of the trunk and of the arm holding the racquet. Fifteen expert tennis players performed six successful serve-and-volleys with both techniques. Running time to the net is significantly lower for FB, whereas V(ball) is significantly higher for FU. Trunk and arm angular momentums about the transverse axis are significantly higher with FU before ball impact. A significant correlation (r = 0.81, P < 0.001) exists between changes in the maximal trunk angular momentum and in running time to the net between the two serve techniques. A significant correlation (r = 0.84, P < 0.001) also exists between changes in the maximal trunk angular momentum and in V(ball) between the two serve techniques. According to these results, FB is the best technique for moving as quickly as possible to the net because of a lower trunk angular momentum.  相似文献   

13.
Purpose: The International Tennis Federation recently launched a worldwide campaign advocating the use of equipment scaling for children learning to play tennis. The aim of this study was to investigate the influence that varying racquet sizes and ball compressions had on children's ability to play a forehand groundstroke. Method: This was a quantitative repeated-measures design experiment. Children were required to perform a forehand hitting task using each of 9 combinations of tennis racquets and balls (i.e., 3 racquet sizes × 3 ball compressions). Children's hitting performance was measured using a points system. The aim for the children was to score as many points as possible. Hitting technique was measured via video replay. Results: Hitting performance was best when the smallest racquet combined with the ball with the least compression was used. The ball with the least compression also promoted 2 technique benefits: swinging the racquet from low to high and striking the ball in front and to the side of the body. Conclusions: This study demonstrated the benefits for young children playing with scaled racquets and low-compression balls. The findings are discussed with regards to their relevance to theories of skill acquisition.  相似文献   

14.
Considerable research has documented that successful performance in interceptive tasks (such as return of serve in tennis) is based on the performers’ capability to capture appropriate anticipatory information prior to the flight path of the approaching object. Athletes of higher skill tend to fixate on different locations in the playing environment prior to initiation of a skill than their lesser skilled counterparts. The purpose of this study was to examine visual search behaviour strategies of elite (world ranked) tennis players and non-ranked competitive tennis players (n = 43) utilising cluster analysis. The results of hierarchical (Ward’s method) and nonhierarchical (k means) cluster analyses revealed three different clusters. The clustering method distinguished visual behaviour of high, middle-and low-ranked players. Specifically, high-ranked players demonstrated longer mean fixation duration and lower variation of visual search than middle-and low-ranked players. In conclusion, the results demonstrated that cluster analysis is a useful tool for detecting and analysing the areas of interest for use in experimental analysis of expertise and to distinguish visual search variables among participants’.  相似文献   

15.
ABSTRACT

This study investigated split-step timing when returning serves and whether this timing is related to neuromechanical capabilities in world-class tennis players. In Experiment 1, the split-step timing of four groups of world-class players (male and female ATP/WTA seniors, and ITF juniors) was measured on court when returning serves of the same level players. The four groups initiated the split-step at a similar time, starting around the time ball-racket contact in the serve stroke and landed when early ball-flight information was available. In Experiment 2, the neuromechanical capabilities (leg stiffness and vertical jump performance) of a group of world-class players and three groups of less-skilled tennis players were examined. The results showed an increase in leg stiffness with an increase in the level of expertise. A cross-experiment analysis in world-class male players (ATP/ITF, n = 10) revealed that the timing of initial foot movement was significantly correlated with the leg stiffness (r2 = 0.54), with later lateral step after the serve in the players who had higher stiffness. The findings support the hypothesis that world-class tennis players adapt perceptual-motor control on the basis of their neuromechanical capabilities and maximise the time before initiating their interceptive action to rely on more reliable information.  相似文献   

16.
The potential effect of fatigue on stroke production in tennis players is still controversial. The aim of this study was to analyse the tennis serve speed and accuracy in prolonged male professional matches played on grass courts. We analysed tennis serve statistics from five-set Wimbledon matches (n?=?15; 30 players). Results showed that match duration averaged 208.3?±?28.3?min. The overall serve speed was 177.0?±?10.2?km/h in the first set and 176.1?±?11.7?km/h in the fifth set (p?=?.34). The difference of all accuracy values of first set serves was not significantly different from those of the fifth set: percentage of valid first serves, 63.1?±?11.1% vs. 62.3?±?11.8%, respectively (p?=?.78); percentage of “aces”, 11.2?±?9.1% vs. 10.0?±?8.9%, respectively (p?=?.39); percentage of “winners”, 2.6?±?7.6% vs. 1.2?±?2.2%, respectively (p?=?.36); percentage of “double faults”, 2.8?±?3.0% vs. 2.8?±?3.4% (p?=?.97). In conclusion, tennis players were able to maintain constant serve speed and accuracy over five-set matches played on grass courts. Professional tennis players are capable of overcoming fatigue and/or make movement adjustments to effectively perform complex technical strokes like the serve throughout matches played on grass courts lasting more than 3?h in average.  相似文献   

17.
Abstract

A tennis skill test for use in quantifying achievement in the forehand and backhand drive strokes was developed and then validated using 76 college women enrolled in beginning tennis classes. The test consisted of returning balls pitched by a pneumatic ball machine into target areas drawn in chalk on a regulation tennis court. Speed of the subjects' shots was assessed by measuring accumulated time in flight for rounds of 10 trials using a stopwatch. A time factor was then employed to correct the target value total for the trials to adjust for ball speed, thus rewarding the more skilled player who could stroke the ball more firmly while still retaining control. The test-retest reliability of the test was found to be .84, while the validity of the test, using judges' ratings as a criterion, was .83. It was concluded that the test was a valid and reliable test of skill which was closely related to the actual game situation. Percentile norms were developed on a limited number of subjects.  相似文献   

18.
Abstract

Variable practice has been shown to be an effective strategy to improve open motor skills. However, the usefulness of this procedure in closed motor skills remains controversial. The following study has the objective of analysing the effects of variability practice in the improvement of a closed skill. The skill studied has been the tennis serve. Thirty young tennis players (13 ± 1.52 years), divided in two groups, took part in this study. One group practiced in variable conditions and the other group in consistency conditions. Both groups performed 12 training sessions (60 serves/session). The variable practice group improved their accuracy significantly compared with the consistency group (F3.25 = 3.078; P = 0.035). The velocity of serve increased after training in both groups (F3.25 = 15.890; P = 0.001). The practice in variable conditions seems to be effective in improving the performance of the tennis serve.  相似文献   

19.
杨天  李哲 《精武》2012,(28):22-22,24
研究目的：随着网球技术高度发展,要求运动员的各项技术更加全面,就发球而言,目前世界高水平男子单打选手在发球落点、旋转和角度准确性的控制等方面较为突出,而在发球决胜局中,特别是在制胜分上在第一次发失误的情况下,如何在第二发中限制对手并迫使对手进入自己的预设的赢球模式显得尤为重要。研究结果和结论：通过分析发现职业网球选手在处理关键分上发球时偏向采用侧旋,以角度、旋转制胜而不是在速度上寻求制胜。  相似文献   

20.
ABSTRACT

Representative Learning Design advocates that practice should simulate the demands of competition. The effectiveness of increased task representativeness to improve serving skill of junior tennis players was assessed after a six-week intervention. Thirty-three participants (15.4 ± 1.9 years of age) were assigned to one of the three groups; “serve only” (participants served to no opponent), “serve return” (participants served to an opponent and hit no extra shots) or “serve +3rd” (participants served to an opponent and hit one extra shot). Using the validated representative practice assessment tool (RPAT) tasks were considered to be low, moderate and high in task representativeness, respectively. Participants hit 56 serves, twice weekly for 6-weeks. Pre and post serving performances were assessed via a skill test and in-situ matchplay using SportsCode and HawkEye ball tracking, respectively. Serve speed, landing locations, serve angle and positional advantage was obtained for 1st and 2nd serves. The relationship between increasing representativeness and increased skill acquisition was not linear, rather different behaviours emerged. For example, when hitting 2nd serves in matchplay, the low and moderate representative groups prioritised speed over placement while the high representative group prioritised placement over speed. Coaches therefore need to carefully individualise representativeness to an athletes’ specific needs.  相似文献   

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