The effect of video‐feedback on the learning of the tennis service by intermediate players

Effects of video‐feedback on improvement of the tennis service were investigated in subjects having at least 2 years of playing experience in tennis. The experiment was carried out in an indoor tennis hall under normal training conditions.

Subjects were randomly divided into three groups: a video‐feedback training (VFT) group, a traditional training (TT) group and a control group, each consisting of 22 subjects. While the subjects of the control group received no training at all, subjects in both the VFT and TT groups were trained twice weekly during 5 consecutive weeks. Each training session lasted 40 min, of which 30 min was spent on actual practice in training of the service. The remaining 10 min was spent on watching, analysing and discussing video recordings of either their own service performed during the training session (VFT group), or ground strokes and volleys of top level players (TT group). Both the VFT and TT group showed significantly greater improvements in both achievement scores and form (technique) scores than did the control group. No differences, however, could be demonstrated between the VFT and TT group, indicating that the subjects of the former group did not benefit from the video‐feedback they received.

While form scores correlated significantly (P < 0.001) with the velocity of the served ball, no such relation between form scores and spatial accuracy was apparent.     

The effect of video-modelling and video-feedback on the learning of the tennis service by novices

This project is addressed to the effectiveness of video mediated instruction on the learning of the tennis service by novices. The research was carried out in an indoor tennis hall under normal training conditions. Three experimental groups were used: a video-model (VMT), a video-feedback (VFT) and a group with a combination of video modelling and video feedback (VMFT). Two control groups - based on different training periods-were also used: a traditional training group (TT1) which practised for a period of 45 min per training session and a second traditional training group (TT2) which practised for a period of only 30 min per training session. All subjects took part in five successive training sessions. No clear advantages of using video mediated instruction methods in teaching novices the tennis service could be demonstrated. Five sessions of 30 min practical training were shown to be as effective as five sessions of 45 min practical training in producing improvements in both form and achievement scores of novice tennis players. While, in the early stages, form and achievement scores were not shown to be significantly related, after five sessions a significant correlation (P less than 0.05) was shown.     

八周非正式正念训练对大学生网球运动技能学习效果的实验研究

通过实验组和对照组的对比研究探讨非正式的正念训练对于大学生网球运动技能学习的影响。研究结果表明,经过8周的非正式正念训练,实验组被试五因素正念量表得分和舒尔特方格测试成绩优于对照组且具有显著性差异,网球技能学习的结果显示,2组被试经过8周的技能学习在动作表现方面没有显著的差异,但是动作的击球结果显示出显著性差异,实验组的有效击球和落点控制的得分优于对照组。由此可见正念训练可以提高大学生的正念水平和注意力水平,促进网球运动技能学习。     

A Comparison of Traditional versus Programed Methods of Learning Tennis

Abstract

Two college service classes, each containing 20 subjects, were taught beginning tennis skills. The traditionally taught Group (Group A), and the programed group (Group B), were first determined homogeneous in height, weight, the Hewitt Revised Dyer Backboard Tennis Test (HRDBTT), and the American College Test before the teaching methods were initiated. After 14 periods of instruction, the groups were compared on various measures. The results of the study indicated that: (1) the general skill level of the groups, as measured by the Hewitt Revised Dyer Backboard Tennis Test, and a single-elimination tournament, was not significantly different; (2) the traditionally taught group improved significantly in general skills while the programed group did not; and (3) the programed group received better subjective rating scores on form than did the traditionally taught group.     

Shoe drop reduction influences the lower limb biomechanics of children tennis players during an open stance forehand: A longitudinal study

Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8?mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (?73%, p?=?.005) but increased peak ankle plantarflexors moment (+47%, p?=?.050) and peak ankle power absorption (+107%, p?=?.005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.     

Can anticipatory skills be learned through implicit video-based perceptual training?

The aim of this experiment was to determine the effectiveness of two video-based perceptual training approaches designed to improve the anticipatory skills of junior tennis players. Players were assigned equally to an explicit learning group, an implicit learning group, a placebo group or a control group. A progressive temporal occlusion paradigm was used to examine, before and after training, the ability of the players to predict the direction of an opponent's service in an in-vivo on-court setting. The players responded either through hitting a return stroke or making a verbal prediction of stroke direction. Results revealed that the implicit learning group, whose training required them to predict serve speed direction while viewing temporally occluded video footage of the return-of-serve scenario, significantly improved their prediction accuracy after the training intervention. However, this training effect dissipated after a 32 day unfilled retention interval. The explicit learning group, who received instructions about the specific aspects of the pre-contact service kinematics that are informative with respect to service direction, did not demonstrate any significant performance improvements after the intervention. This, together with the absence of any significant improvements for the placebo and control groups, demonstrated that the improvement observed for the implicit learning group was not a consequence of either expectancy or familiarity effects.     

Cardiorespiratory,hormonal and haematological responses to submaximal cycling performed 2 days after eccentric or concentric exercise bouts

The aim of this experiment was to determine the effectiveness of two video-based perceptual training approaches designed to improve the anticipatory skills of junior tennis players. Players were assigned equally to an explicit learning group, an implicit learning group, a placebo group or a control group. A progressive temporal occlusion paradigm was used to examine, before and after training, the ability of the players to predict the direction of an opponent's service in an in-vivo on-court setting. The players responded either through hitting a return stroke or making a verbal prediction of stroke direction. Results revealed that the implicit learning group, whose training required them to predict serve speed direction while viewing temporally occluded video footage of the return-of-serve scenario, significantly improved their prediction accuracy after the training intervention. However, this training effect dissipated after a 32 day unfilled retention interval. The explicit learning group, who received instructions about the specific aspects of the pre-contact service kinematics that are informative with respect to service direction, did not demonstrate any significant performance improvements after the intervention. This, together with the absence of any significant improvements for the placebo and control groups, demonstrated that the improvement observed for the implicit learning group was not a consequence of either expectancy or familiarity effects.     

Audio,Visual, and Audio-Visual Instruction with Mental Practice in Developing the Forehand Tennis Drive

Abstract

The effectiveness of mental practice was studied when combined with three variables of instruction: audio, visual, and audio-visual presentations of the forehand tennis drive. An adaptation of the Broer-Miller tennis test was administered to 183 subjects prior to and following the training sessions. Subjects were divided into six experimental groups and one control group. Of the experimental groups, one heard, one viewed, and one both heard and viewed a sound filmstrip which described the tennis drive. Three similar experimental groups received parallel instruction but also engaged in 10-min. mental practice sessions immediately following their respective presentations. All six groups met three times a week for a period of 8 weeks. The three experimental groups which also engaged in mental practice showed a significant improvement in the execution of the forehand drive. Among the variables of instruction, audio used in conjunction with mental practice proved to be the most effective method for development of the forehand tennis stroke.     

Videotape Replay and the Learning of Skills in Open and Closed Environments

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.     

Acute effects of two different tennis sessions on dorsal and lumbar spine of adult players

The aim of the study was to evaluate the dorsal and lumbar spine of expert and recreational tennis players before (pre) and after (post) two different training sessions. The sample consisted of 17 male tennis players, nine expert and eight recreational males (age 21.2 ± 1.6 years). We assessed the back surface by rasterstereography pre and post two different training sessions both lasting 1.5 h: a standard training and a specific over-shoulder shots training session, respectively. Lordotic and kyphotic angle, length, imbalance, inclination for trunk, pelvic torsion, left and right lateral deviation and surface rotation were measured. Tennis expertise (expert versus recreational) significantly affected the surface rotation and right lateral deviation (P < 0.05). Trunk length was affected by intervention (pre versus post) (P < 0.05). Left lateral deviation differed both for type of session (session 1 versus session 2) and intervention (P < 0.001, P < 0.05). Expert tennis players had higher values on surface rotation and right lateral deviation, around or just above physiological values (0–5° and 0–5 mm, respectively). Type of session significantly affected left lateral deviation, indicating that over-shoulder shots lead to a higher stress for the spine; the workload produced by both single sessions led to a shortening effect on trunk length. A single training session can induce acute modifications in some parameters of dorsal and lumbar spine of players.     

Acquiring an attacking forehand drive: the effects of static and dynamic environmental conditions

Two groups of 10 novice subjects each were trained to perform attacking forehand drives in table tennis and land the balls as fast and as accurately as possible onto a target on the opposite side of the net under two different training conditions. Under the static training condition, the balls were to be struck from a constant position, and under the dynamic training condition, balls approached the subjects in a normal way. Both groups were tested under dynamic conditions prior to and after four days of training, during which they received 1,600 practice trials. Both groups of subjects were shown to increase the number of balls that landed on the target, and learning was also evident from an increased consistency of the direction of travel of the bat at the moment of ball/bat contact. However, no increase in consistency was found for the location of the bat at the moment of ball/bat contact and for the movement times. Thus, learning can occur in the absence of externally generated time-to-contact information, but this is not due to the establishment of a consistent movement form. Learning appears to progress from control at the moment of ball/bat contact backward, toward the moment of initiation.     

Effect of Selected Motive-Incentive Conditions upon Development of Strength through an Isometric Training Program

Abstract

This study was made to determine the influence of five selected motive-incentive conditions upon the effectiveness of a 6-week isometric training program for the development of strength in the elbow flexor muscle group. Data were obtained from an initial test, from each training session, and from a final test. The mean gains in best strength scores from the initial to the final test were statistically significant (p = .05) for all five motive-incentive groups. No significant differences (p = .05) were found between the mean of the scores for the five motive inventive groups obtained during the first training session, during the last training session, from the final test, and from the cumulative scores for the 12 training sessions.     

Tactical proficiency among table tennis players with and without intellectual disabilities

Abstract

The effect of intellectual impairment on sports performance has received limited attention by researchers. As a contribution to closing this gap, the purpose of the present investigation was to examine the differences in tactical proficiency between table tennis players with and without intellectual disabilities (ID). These groups were matched for training-volume and experience and consisted of 41 male (age = 27±8) and 30 female (age= 28±8) elite players with ID and a reference group of 12 male (age= 24±12) and 5 female (age= 20±9) players without ID. In two different test settings – one a World Championship and the other a training camp – the players in each group performed 60 semi-standardised rallies against the same opponent. Players were told that 12 sets of five identical services would be delivered, and their goal was to return the service with the intention of ‘winning the point’. The test results were validated for this study, to compute tactical proficiency scores (maximal score of eight points) for each player. A two-way Analysis of Variance (ANOVA) revealed significantly lower proficiency scores for players with ID than for those without ID. Repeated-measures ANOVA revealed that within each series of five rallies, starting with identical services, all participants were able to significantly improve their tactical proficiency gradually, but players without ID scored 4.3±0.5 from the first ball on, and while athletes with ID only 3.3±0.7 after five balls. The results of this study indicate that ID is associated with decreased tactical proficiency in table tennis.     

Trampoline Versus Resistance Training in Young Adults: Effects on Knee Muscles Strength and Balance

ABSTRACT

Purpose: Trampoline parks are becoming popular in many countries, providing recreational facilities for children and adults. This study investigated the effects of trampoline training on knee muscles strength and balance in young adults. Methods: Twenty-six participants (14 males, 12 females) were randomized into trampoline training (TT) and resistance training (RT) groups to undergo a 6-week supervised intervention program (2 × 30 min per week). TT group performed basic trampoline exercises while the RT group performed resistance training targeting lower extremities muscles. Peak knee extension and flexion torque, postural sway characteristics, and Y balance test (YBT) performance were evaluated before and after the intervention. A mixed model analysis of variance (group × time) was applied. Results: After training there were significant improvements in knee extension torque (mean difference_post-pre [95% CI], TT: 0.27 [0.00, 0.54] N?m/kg, RT: 0.31 [0.09,0.54] N?m/kg, p = .001), knee flexion torque (TT: 0.25 [0.17,0.33] N?m/kg, RT: 0.21 [0.08,0.34] N?m/kg, p < .001), and dynamic balance (YBT composite scores, mean difference_post-pre [95% CI], TT: 4.9 [?0.3, 10.2]%, RT: 5.2 [2.4,8.0]%, p = .001). No difference between groups was found. Conclusion: Trampoline training can be as effective as resistance training for improving knee muscles strength and dynamic balance in young men and women.     

乒乓球训练对男童体质影响的研究

本文采用实验法,通过选取40名3-4年级的小学生,分为实验组和对照组,实验组进行半年的乒乓球训练,测量各人的体质数据。结果：坚持参加乒乓球训练的男童腿部力量明显大于未参加乒乓球训练的男童,视觉反应时和听觉反应时明显低于未参加乒乓球训练的男童,但身高和大腿围和小腿围等身体形态并无显著差异。结论：坚持乒乓球训练可以增强男童的体质。     

A Comparison of Two Methods of Teaching the Tennis Serve

Abstract

This study was designed to compare the effectiveness of two methods of teaching the tennis serve. College women (N=123) in six tennis activity classes at Georgia Southern College participated. The experimental group of 60 students started serving from the service court line and were gradually moved back to the base line. The control group of 63 students began serving from the base line in the traditional manner. After five weeks of practice both groups were given the same tennis serving test for accuracy and speed. The study showed no significant differences in the two teaching methods.     

比赛法在高校乒乓球教学中的实证研究

采用文献资料法、实验法、问卷调查法、数理统计法等方法,对在乒乓球选项课教学中采用比赛法教学进行实证研究。选取了实验班和对照班经过一学期的教学实验,再进行有关体育统计学的分析和问卷调查。主要结论：正手攻球技术、发球技术的成绩实验组优于对照组,统计学意义上成绩有显著差异;反手推挡技术成绩实验组差于对照组,差异显著,具有统计学意义;在教学中穿插比赛法不会影响正常的教学工作,有助于提高学生学习的兴趣和积极性,能够完成教学大纲的要求,对教学质量提高有一定的促进作用。     

Relative Effects of Isokinetic and Plyometric Training on Vertical Jumping Performance

Forty-eight volunteer males were randomly assigned to one of three groups. Group I trained with isokinetic exercises, Group II trained with plyometric exercises, and Group III was the control. Subjects in the training groups trained three times per week for 8 weeks. The isokinetic group performed three sets of 10 repetitions per set of leg presses each training session. The plyometric group performed three sets of 10 repetitions per set of depth jumps from a height of 34 inches, with added resistance beginning with weeks 3, 5, and 7 of 10, 15, and 20 pounds, respectively. Prior to and at the end of the training period, all subjects were given a vertical jump-and-reach test. Covariance analysis was used to compare posttest scores with the effect of pretest differences removed. Results showed both training groups improved significantly in vertical jump capacity; however, no significant difference existed between training groups.     

Quantification of the physiological loading of one week of "pre-season" and one week of "in-season" training in professional soccer players

The aim of this study was to quantify the physiological loads of programmed "pre-season" and "in-season" training in professional soccer players. Data for players during each period were included for analysis (pre-season, n = 12; in-season, n = 10). We monitored physiological loading of training by measuring heart rate and rating of perceived exertion (RPE). Training loads were calculated by multiplying RPE score by the duration of training sessions. Each session was sub-categorized as physical, technical/tactical, physical and technical/tactical training. Average physiological loads in pre-season (heart rate 124 ± 7 beats · min(-1); training load 4343 ± 329 Borg scale · min) were higher compared with in-season (heart rate 112 ± 7 beats · min(-1); training load 1703 ± 173 Borg scale · min) (P < 0.05) and there was a greater proportion of time spent in 80-100% maximum heart rate zones (18 ± 2 vs. 5 ± 2%; P < 0.05). Such differences appear attributable to the higher intensities in technical/tactical sessions during pre-season (pre-season: heart rate 137 ± 8 beats · min(-1); training load 321 ± 23 Borg scale · min; in-season: heart rate 114 ± 9 beats · min(-1); training load 174 ± 27 Borg scale · min; P < 0.05). These findings demonstrate that pre-season training is more intense than in-season training. Such data indicate that these adjustments in load are a direct attempt to deliver training to promote specific training adaptations.     

Acquiring an Attacking Forehand Drive: The Effects of Static and Dynamic Environmental Conditions

Abstract

Two groups of 10 novice subjects each were trained to perform attacking forehand drives in table tennis and land the balls as fast and as accurately as possible onto a target on the opposite side of the net under two different training conditions. Under the static training condition, the balls were to be struck from a constant position, and under the dynamic training condition, balls approached the subjects in a normal way. Both groups were tested under dynamic conditions prior to and after four days of training, during which they received 1,600 practice trials. Both groups of subjects were shown to increase the number of balls that landed on the target, and learning was also evident from an increased consistency of the direction of travel of the bat at the moment of ball/bat contact. However, no increase in consistency was found for the location of the bat at the moment of ball/bat contact and for the movement times. Thus, learning can occur in the absence of externally generated time-to-contact information, but this is not due to the establishment of a consistent movement form. Learning appears to progress from control at the moment of ball/bat contact backward, toward the moment of initiation.