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Longer-Reach Table Tennis, a New Thinking
George Segun1 and A. L. Toriola2
1 ITTF Executive Vice President, Nigeria 2 HYPERLINK, South Africa
Following the keynote address given in Kuala Lumpur, an idea of a possible new table tennis event is now being experimented with. The philosophy behind this new thinking is an increase of the overall playing length achieved through separation of the two halves of the table by a gap which may be adjusted from 0 cm to infinity. Local experiments already carried out suggest (a) compulsory long service is equal in length to minimum the size of the gap (b) longer rallies (c) attractive lobs.
A number of tests have been designed in the field of kinesiology with the purpose of achieving the above desirable positive effects. Also, it is hoped that with the variation of the gap sizes, distinctive categorization of play in different age groups will be possible when endurance test limits are established.
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Recent Problems with Equipment
J. Rufford Harrison
ITTF Equipment Committee Chairman, United States of America
This paper will discuss several problems that currently face the Equipment Committee;
The problem of changing from the 38mm ball to the 40mm balls is largely behind us, but for some months, until the manufacturers perfect their changed techniques, we cannot expect the quality that we have come to expect in the 38mm ball. Tables We have recently received complaints about deteriorating and variable quality of tables, largely associated with friction. Of all the properties of the table, this happens to be the most difficult to measure. We shall probably have to develop dynamic tests, which will be more costly. Racket coverings Both the Executive Board and the Council have expressed displeasure at the large number of authorised racket coverings, and we have been asked to find a way to shorten the list. Several possible ways will be discussed. Speed glue When "speed glue" was first introduced, it contained solvents that were toxic, even possibly carcinogenic. We therefore had to devise tests to detect the offending solvents, and to place upper limits on the permissible concentrations. The resulting Dräger-tube method is fairly simple to operate, and not too costly, but it does have problems. Detecting any solvent is far easier than detecting certain specified ones. Our preferred solution is to ban the presence of any solvent. Colour and Lighting Another task that we have been given is to prescribe the optimum colour scheme for our sport, for both TV viewers and those in the hall. Orange or white ball? Blue or green table? Red floor or some other colour? Net? Surrounds? A difficulty here is the effect of the lighting, which is always different from one event to another, and which affects the perceived shade of a colour and the amount of haze.
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Doping Control by the ITTF from 1990
Jean-François Kahn ITTF Sports Science Committee Chairman, Laboratory of Physiology, CHU Pitié-Salpétrière, Paris, France
With the exception of the 34th WTTC held in Birmingham (UK) in 1977, 1990 is considered to be the actual starting point of the ITTF anti-doping program, when Mr. Ichiro Ogimura, ITTF President, decided to officially appoint a person in charge of this matter. The first meeting was organised in September 1990 in Tokyo (Japan) a few months before the 41st WTTC in Chiba (Japan). At that time, players (event at high level), coaches and officials held a low opinion and were rather doubtful about the usefulness of dope testing in table tennis, and in some cases had no knowledge about it at all. Since then, the anti-doping program has been progressively implemented. The first part was the elaboration of rules. They are based on the IOC Anti-Doping Code and constitute chapter 5 of the ITTF Handbook, and the testing procedures are described in detail in the Technical Leaflet T13. The second part of the program is the spread of information among the different categories of participants to convince them not to use unauthorised substances and/or methods. The information has been circulated and will continue to be circulated among people involved in table tennis training and competition, whatever their level of play, especially the young players. Regarding the dope testing itself (the third part of the program) everyone is aware nowadays that players may be subject to testing during any competition under the ITTF authority, and in some cases even during a training session, as out-of-competition testing has become a full part of the ITTF anti-doping program since the year 2000. For example, from Chiba (1991) to Kuala-Lumpur (2000), 271 tests have been carried out during all the world championships, and in the weeks preceding the Olympic Games in Sydney, 28 out-of-competition tests have been conducted on qualified players with the collaboration of the World Anti-Doping Agency (WADA). As in any other field regulated by specific rules, people (not only players) who do not respect the limits fixed by these rules are subject to penalties the application of which may be extended at different levels (national and/or continental and/or international and/or IOC levels).
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Information Processing and Decision Making in Table Tennis: The Factors of Expertise
Hubert Ripoll
Faculté des Sciences du Sport, Université de la Méditerranée, Marseille, France
In table tennis the player is confronted with situations of which the extreme high level of informational constraints generally overflows the resources and the processing capacities used by human beings in usual life situations. For instance, the player has to gaze at a ball flying at near 300 °/s. while its maximal capacity of oculomotor pursuit is about 50 °/s. Also, the duration between two strokes is sometimes less than 300 ms. while reaction time for triggering the same complex technical gesture, like the one carried out in the field, needs, in the condition of the laboratory, more than 400 ms. These paradoxes can be explained by considering that expert players adapt their bio-informational system of processing to the non-usual constraints of table tennis situations. The aim of this paper is to describe these adaptations. We will describe two sectors of the game concerning on the one hand, the behavior involved in the act of hitting the ball and on the other hand, the strategies involved in decision-making. We will address the following major question: does the adaptation of the players result from a transformation of the software or of the hardware of his bio-informational system of processing?
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Motor Unit Recruitment and Metabolic Responses Using the New Bigger Ball in Table Tennis
Jeong B. Park, Cheol U. Kwon and Chang K. Kim
Human Physiology, Korean National University of Physical Education, 88-15 Oryun-dong, Songpa-gu, Korea
We examined the influence of ball size on motor unit recruitment pattern and metabolic responses during regular training in table tennis. Eight university table tennis players performed a 30 min sequence of regular daily training consisting of three 10 min periods of different strokes. Samples were obtained from both thigh and shoulder muscle groups before and after exercise. The girths of the thigh and crus were unchanged, but differences were found in the antebrachium and brachium in the playing arm. No clear difference was demonstrated in motor unit recruitment pattern in the leg and shoulder muscles between using the smaller or bigger balls. The mean occurrence of type I fiber in quadriceps and deltoid muscles was found slightly higher in deltoid muscle (44% VS 49%), whereas an inverse trend was shown in type IIx fibers in the same muscle (22% VS 13%). The heart rate reached 183-186 bpm after 30 min of exercise and remained slightly higher with the bigger ball from 10 min of exercise till the end of the experiment. The ventilatory response and oxygen uptake were proportional to the heart rate. No difference was observed in blood lactate concentration between ball sizes, but the recovery rate was faster with the bigger ball.
In conclusion, the present study demonstrated that motor unit recruitment and metabolic responses were similar with the smaller and bigger balls in table tennis.
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Prediction of Rebound Power of Table Tennis Racket - Comparison between the 40 mm and the 38
mm Balls -
Saitama Institute of Technology, Okabe, Osato, Saitama 369-0203, Japan
Key words: 40 mm ball, rebound power, impact force, contact time, deformation
This work predicts the effect of the larger 40 mm ball on the impact force, the contact time, the deformation of the ball and rubber, and the rebound power coefficient associated with the impact between the racket and the ball, when the impact velocity and the impact locations on the racket face are given. It is based on the experimental identification of the dynamic characteristics of the ball-racket system and an approximate non-linear impact analysis, where the contact time is determined by the natural period of the whole system comprising of the mass of the ball, the nonlinear stiffness of the ball and rubber, and the reduced mass of the racket at the impact location on the rubber face. It also considers the energy loss during impact between the ball and the rubber. The racket performances obtained regarding the rebound power with a 40 mm ball were compared to those with a 38 mm ball using a racket (BISIDE) with mass of 171 g including 79.5 g of the rubbers (Sriver) Compared to the 38 mm ball, the impact force with the 40 mm ball is slightly larger, the contact time is shorter below 15 m/s and longer above 15 m/s of impact velocity, the deformation of the ball is much larger but that of the rubber is almost the same, and the rebound power coefficient is slightly larger below 20 m/s but smaller above 20 m/s of impact velocity. Accordingly, the post-impact velocity of the 40 mm ball is slightly faster below 20 m/s of impact velocity and slower above 20 m/s compared with those of the 38 mm ball. Since the drag force of the 40 mm ball should be larger than that of a 38 mm ball, the velocity of the 40 mm ball should be slower.
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Distribution of Contact Points on the Racket with 40mm Balls
Hisao Ishigaki
Aichi Institute of Technology, Yakusa, Toyota, Aichi 470-0356, Japan
Two experiments were performed on 40mm balls.
1. The velocities of 40mm balls (2.7g) and 38mm balls (2.5g) were measured by propelling the balls from a table tennis machine at three projection speeds: high, middle and low. Hardly any difference was shown in ball velocity between the 40mm ball and the 38mm ball at any of the projection speeds. This result agreed with that of the velocity simulation by Tsuji et al (1999) using a personal computer.
2. Using 14 college table tennis players, the contact points on the racket were investigated. Each player hit a 40mm ball and a 38mm ball 40 times respectively and the centre of distribution for the 40 contact points was calculated. The results showed that the centre of distribution moved closer to the racket centre (away from the top edge) with the 40mm ball than with the 38mm ball. The mean distance of movement was about 6mm among the 14 players. This phenomenon was observed in almost all the players, both pen holder and the shake hand. It is surmised that the increased ball weight requires the players to hit the 40mm ball at a point closer to the racket centre to overcome the increased ball pressure.
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Effect of the 40 mm Diameter Ball on Table Tennis Rallies
Toshiko Takeuchi 1, Yoshio Kobayashi1, Shuichi Hiruta2 and Nobuo Yuza3
1 Chukyo University, Kaizu, Toyota, Aichi 470-0348, Japan 2 Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-0814, Japan 3 Chukyo Women’s University, Obu, Achi 474-0011, Japan
Recently, the ITTF adopted a 40 mm diameter ball (2.7g) for table tennis matches believing this might decrease the ball speed typically appointed by the traditional 38 mm ball (2.5g), and consequently the rallies may last longer. The longer rallies may increase the interest of table tennis spectators and TV viewers. The purpose of this study was to compare the newly adopted 40 mm ball to the conventional 38 mm ball to determine whether diameter differences cause differences in number of hits per rally (rally counts). Rally counts for the 38 mm ball were conducted in the All Japan Championships in 1993 and those for the 40 mm ball in the same competitions in 2000. The rally counts for the 38 mm ball were taken from the quarterfinals and the semi-finals in both men’s and women’s singles and from the semi-finals in both junior men’s and women’s singles. The rally counts for the 40 mm ball were taken from the quarterfinals and the semi-finals in both men’s and women’s singles and from the quarterfinals, the semi-finals and the finals in both junior men’s and women’s singles. The defensive players’ matches were excluded. In addition to the rally counts, a questionnaire was given to the participating players to subjectively evaluate differences in spinning, speed, resistance, etc. of the 40 mm ball as compared to 38 mm ball. The mean of a sample of rallies per match was 3.1 vs. 4.1 in men, 3.8 vs. 4.6 in women for 38 mm and 40 mm balls respectively. The same counts were 3.0 vs. 3.3 in junior men and 3.6 vs. 4.6 in junior women. The combined means for men and junior men, and women and junior women were 3.1 vs. 3.8, and 3.7 vs. 4.6 for 38 mm and 40 mm balls respectively. The frequency distribution for the rally counts in all groups for both the 38 mm and 40 mm balls were concentrated toward the low end of the scale. The mean values for the above rally counts were each significantly higher for the 40 mm ball. The questionnaire indicated that: 1) 79% of the players felt that it was more difficult to induce spin in the 40 mm ball than the 38 mm ball 2) 80% considered the 40 mm ball speed to be slower 3) 73% considered the 40 mm ball to be heavier
These characteristics of the 40 mm ball may be associated with the longer rallies because it is easier to return the larger ball. In conclusion, the rallies during table tennis matches are lengthened with a 40 mm ball, which may result from slower flight and spin characteristics of the larger ball.
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Characteristics of Rallies in Table Tennis with 40mm Diameter Balls
Haipeng Tang1, Masato Mizoguchi2, Iwao Matsumoto2, Kazuo Sato2, Shunji Shimizu2 and Shintaro Toyoshima1
1 Aichi Prefectural University, 1522-3 Nagakute, Aichi-gun, Aichi 480-1198, Japan 2 Toyama Industrial Technology Center, Higashi-tonami, Toyama 939-1503 Japan
The size of the ball has been changed by the ITTF and the new ball has been used officially since October 2000. The diameter of the ball was enlarged from 38 mm to 40 mm and the weight from 2.5g to 2.7g. It is expected that this will change the playing style and the tactics. The purpose of this study was to compare the hitting properties of the new ball (40 mm) and the old ball (38 mm) in order to show the effects to the players. The ball speed from the hitting point to the receiving point was calculated by using a serving machine (robot) and a speed measurement system. Initial velocities and ball spins were calculated by using a golf-swing robot and a high-speed video camera. The robot arm was equipped with a racket which hit the balls at various speeds and angles. Three kinds of shots (drive, chop and serve) were made in the rallies by skilled players, and average values of rally times for the two kinds of balls were measured.
The following results were obtained; (4) The initial speed of the new ball was 1-2%, and the ball spin 5-20%, less than those of the old ball. (5) The difference of the reduction ratio of speed between the new ball and the old ball was not observed. (6) The average rally times of the new ball for both drives and chops were 2-4% longer than those of the old.
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Speed and Spin Characteristics of the 40 mm Table Tennis Ball and the Influence on Elite Players
Wei Xie1, Kong Chuan Teh1 and Zhifeng Qin2
1 Singapore Sports Council, 15 National Stadium, 397718, Singapore 2 Singapore Table Tennis Association, Toa Payoh, 319389, Singapore
The 40mm table tennis ball has been used since October 2000. Coaches and players have been talking about the differences in speed and spin between the large (40mm) and small (38mm) ball. It is very important for players to understand these differences before they change their techniques to adapt to the large ball. The aim of this study is to identify the characteristics of the large (40mm) ball. In this study, Singapore elite players received both top-spin and back-spin balls from the robot (NEWGY ROBO-PONG 2040). Three video cameras (Peak HSC-200) captured data for three-dimensional motion analysis at a rate of 200 fields/second. This was conducted in December 2000, after the players had been using the large ball for three months. Both speed and spin of 38mm and 40mm balls were calculated using Peak Motus v 4.3. The male and female players all of different styles and different techniques including attack, loop and service, were analysed and compared quantitatively, for example, the difference in speed and spin for forehand smash and forehand high loop. The loss of the speed and spin in the air was also considered. Finally, the influence of these differences on elite players was discussed.
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Differences Caused with the New 40 mm Ball in Structure of Competitive Activities of Top Table Tennis Players
Zoran Djokic
Faculty of Physical Education, University of Novi Sad, Yugoslavia
The subject of this research is the structure of competitive activities in a sample of about 90 top table tennis players (mostly players in the first 100 of the ITTF Ranking list ) in the 2000/2001 season, during several competitions. The results are compared with those of previous research (Structure of competitors activities of top table tennis players; Master thesis at Faculty of Physical Education, University of Novi Sad YUGOSLAVIA, 1999.) in the 1996/97, 1997/98 and 1998/99 seasons. Competitors activities were analysed in 61 activities, in 3 groups of activities: 1. System of variables for evaluation of frequency, way of realisation and effectiveness of technical and tactical elements (30 variables): frequency of technical and tactical elements; effect of these elements; stroke placement zone; stroke realization zone. 2. System of variables for evaluation of effectiveness of service stroke (and return of service) and effectiveness after service stroke (and returning service) (23 variables): effectiveness of service stroke (type of service and service placement zone); effect of service stroke and activity after the service; type of return; effect of returning stroke 3. System of variables for evaluation of movement activities (8 variables): side and deep movements; change of forehand and backhand position; stroke in forehand/backhand position and arm swinging for forehand/backhand strokes. Research consists of the analysis of activities for all players, from the aspect of success in play (winners and losers), and quality of players (position on ITTF Ranking list). For every analysed activity basic statistical data, frequency data, percentage in complete activity and group of activity, are determined as characteristics from the aspect of success of play and quality of player. The basic aim of this research is rationalization and higher effectiveness of training processes in table tennis. One of the products of this work is a software for analysing table tennis match which will be presented (DJ2001, co-produced with TIBHAR).
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The Use of the 40 mm Table Tennis Ball by the University of the Philippines Varsity Table Tennis Team
Oscar Yoshihiro Santelices
University of the Philippines, Diliman, Quezon City, Philippines
The study investigated the use of the 40mm table tennis ball as experienced by the University of the Philippines Varsity Table Tennis Team during the 1st U.P. 40 mm Ball Table Tennis Championships held October 18 to 20, 2000, the first official local tournament using the 40mm ball. It also determined the significant effect of the new ball on the performance of competitive players. Thirty-one players (21 male and 10 female) were given a 59-item questionnaire on the following areas: 1) Service, 2) Receive, 3) Offence, 4) Defence, 5) Individual Styles and Techniques, 6) Tactics and Strategies, and 7) Other. The responses were rated on a 5-point Likert Scale and analysed using the descriptive method. The results showed that 71% of the respondents improved their games mainly because the ball is slower and anticipation is easier. 67.7% prefer the 40mm ball to the 38mm ball while 83% could easily adjust to it. The t-test showed that there is a significant difference between male and female players at p<0.05. No significant differences were noted between power and speed or agility and timing. Varsity level players who are less skilful than the regional and international competitors considered the 40mm ball most effective in defence since the ball is slower. The regional and international level players, however, experienced a big difference in terms of the speed of the ball in general. Due to the bigger diameter and weight of the 40mm ball, physiological factors were of significant importance. In conclusion, the data indicated that Filipino table tennis players welcome the 40mm ball given the proper time for adjustments. Further studies are still under way to find more conclusive results.
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The Role of the Coach
Chandra Madhosingh
Department of Curriculum Studies, Faculty of Education, Vancouver, B.C., V6T 1Z4, Canada
In this session I intend to cover the main tasks and expectations of the coach, as prescribed by Canadian standards. These will include:
- The Philosophy of Coaching - Goals of the Programme - Reasons for Participating in Table Tennis - Use of Table Tennis questionnaires - Developing positive self-image - Fair play and the Laws of Table Tennis - The Training Facilities and Safety; Sport Science - The Yearly Planning Instrument for Table Tennis
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An Evaluation of Training and Tactics of Chinese Table Tennis Players
Xiaopeng Zhang
National Research Institute of Sports Science, Beijing 100061, P. R. China
Chinese players swept up the gold medals in the 27th Olympic Games in Sydney, Australia, after doing the same in Atlanta in 1996. In order to give more support to the Chinese table tennis team, a scientific group was organized in 1998 to focus on how to use tactics against different opponents in the Olympic Games. The contents of the study are as follows. 1. Building up a Data-base In order to make the study of the recent years’ results more systematic and to simplify the comparative analysis, a base with 50,000 pieces of data has been built up, supplying as much material as possible for the coaches, players and researchers 2. Improving Methods For a long time, matches have been analysed by considering these phases: attack after service, receive and rally. This method has been proven to be effective by the comparative study on table tennis tactics. Owing to changes in table tennis styles and techniques, the evaluation standard and the nature of the phases had to be corrected as the sport developed. 3. A Comparative Analysis of Tactics Knowing the opponent and setting up one’s own playing schemes to deal with them is very important for a player to win the match. The comparative study between Chinese and foreigners is therefore the main task for the scientist in the Chinese team. This study includes playing styles, strong techniques, weak techniques, the opponent’s placements and the ways to play against China. Data and edited videotape were supplied to the coaches and players to illustrate repeatedly with SP and LP to inform to the players about their opponents. To master the opponents’ tactics, effective training methods can be chosen pointing to the different players’ styles. It was proved in the Olympic Games that the choice of techniques used by the Chinese players were quite correct. 4. Training Evaluation To help coaches know more about the players practice in preparation for the Olympic Games, the effect of training was evaluated through the calculation of data including the effective training time of each class, rally numbers of each point, winning and losing rates for each training plan, competitive ability in the practical matches and the extent of fatigue and concentration of the brain. The results with suggestions were written up and handed out to the coaches and players to improve the training in the next session. 5. Technical Archives Based on the acquired data, technical archives of the opponents are compiled to explain clearly the tactics, technical characters and patterns to the coaches and players. The archives can be looked up at any time and some key contents will be memorized by the players’ heart. Up to now, there have been 48 files with 50,000 words of the main opponents in the Chinese table tennis team. These technical archives supplied much important information for the development of effective playing plans for the Chinese players in the Sydney Olympic Games. With the hearty collaboration of coaches, players and researchers, much useful and important work has been done, which gives strong scientific support to the sweep up of gold medals by Chinese table tennis players in Sydney.
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The Filming of Table Tennis
Jota Ito
Sony Corporation, Japan
It is obvious that TV broadcasting has contributed to the accessibility and growth of modern sports. However, the TV camera can rarely capture the dynamics of the fast moving sport of table tennis. Camera techniques for capturing the action and skill of table tennis are not good enough to attract the attention of the sports public. Therefore, I studied the best way to film table tennis, in order to make it a true major sport. There are three important considerations when filming table tennis: showing the clear and complete path of the ball from racket to racket, filming the player and the table in full frame, and filming the true speed of the ball (I named these the CFS criteria). Because table tennis is a small-scale sport, advanced camera techniques must be used to zoom in and show the true speed of the ball. Focusing my attention on these considerations, I began to analyze how to address the special camera techniques needed for filming table tennis. First, I simulated TV images by calculating various camera positions in relationship to the field of play and the image to be filmed. Next, I evaluated actual broadcast images. The actual broadcast removed the camera so far from the game that the image appeared to be only two-dimensional: player to player ball movement only. The result is that we do not experience the true speed of the ball. Analyzing these problems, I will present the best camera position, which can capture the speed and movement of the game, and how to achieve it. Additionally I will address some idea for improving film editing and sound.
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Popularization of Table Tennis as Family Sport
Vladimir Schlamberger
ITTF Media Committee, Slovenia
How can the interest in table tennis in Slovenia be regained? It was the top sport in the country in 1965, when the World Table Tennis Championships was held for the first time in Yugoslavia or the Balkans. This is the goal of the experts of the Slovenian Table Tennis Association, an association in a small country. Table tennis has a 73-year long history in Slovenia, which is one of the former Yugoslav Republics. It has been independent since 1991. There are 1.99 million inhabitants and the capital is Ljubljana. We have 49 table tennis clubs with more than 600 members, and thousands of enthusiasts playing in companies, schools and other places. Main tournaments are the Slovenian Open in Velenje, the Slovenian Youth Open in Ljubljana and an International Veterans Event in Ljubljana). The well-known Slovenian sports expert Dr. Miran Kondric believes that the chance for an increased interest of table tennis in Slovenia is possible. Anyone can play, from 6-year old children to 94-year old seniors, so the sport could be interesting and amusing for all members of the family. In Slovenia we have a special kind of amusing play - cross table tennis. This is a game for five or more players, who run around the table hitting the ball one after another. Partly successful was a program run for the last three years, named 5000 ping-pong bats. Former table tennis representatives, sport teachers, table tennis officials, businessmen and politicians visited ten schools, even preschools (children aged 5 years old), played in exhibitions and various sponsors donated ten, twenty or more table tennis rackets, balls and equipment for future table tennis players.
This paper describes this program and our attitude towards table tennis as a family sport.
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Computer Supported System for the Evaluation of Fitness of Slovenian Youth Table Tennis Players
Miran Kondric and Bojan Lesko
Faculty of Sport, University of Ljubljana, Slovenia
Key words: table tennis, computer
This paper describes the use of computer software for the evaluation of the fitness of Slovenian junior table tennis players. A Sport Measurement Management System (SMMS) has been developed to determine the optimal morphological and motor condition for table tennis players. In our case, 36 top male and female junior players in Slovenia were subjected to several morphological and motor tests, enabling us to observe the state of development of the player. We also discuss the importance of the test in determining the level of a player’s pre-dispositions (talent) for table tennis and in evaluating his readiness or the effectiveness of his training. In the second part of the paper there is an overall presentation of the SMMS program, the hardware and software requirements for its use, its database and a number of presentations and reports on its applications in table tennis. If we compare the data with those for juniors in other racket sports, we can see that there is considerable potential in the motor status of Slovenian table tennis players. Especially important are the longitudinal data on this status and evaluation of the results gained over a longer period of time. This information is necessary for good planning of the training process and its connection with the morphological status of a player. With the SMMS program, table tennis coaches can regularly follow the results of morphological and motor measurements on the one hand, while on the other hand they can obtain an analysis of the results and an evaluation based on different models (Z-value and ND-models).
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Slide Aerobic Exercise in the Table Tennis Physical Conditioning Program
Gordana Furjan-Mandi1, Miran Kondric2, Nikola Rausavljevi3 and Boris Metiko1
1 Faculty of Physical Education, University of Zagreb, Croatia 2 Faculty of Sport, University of Ljubljana, Slovenia 3 Faculty of Natural Sciences, Mathematics and Education, University of Split, Croatia
All kinds of aerobic exercise programs are extensively implemented in sports recreation. A trend to increased application of these exercise systems is noticeable in areas of physical education, kinesitherapy, and even in top-quality sport. Aerobics has therefore become generally interwoven through all areas of physical culture. It is well known that aerobic classes of what ever type are powerful training units with regard to the components of the work-out load volume. This explains significant changes in functional, motor and morphological features in individuals induced by participating in the systematic aerobic exercising. The authors present a new form of aerobic training and its basic theoretical premise as a constituent part of physical conditioning. An aerobic training program is proposed that is appropriate to be included as one segment of the physical conditioning of table tennis players. On the basis of slide aerobics three aerobic training programmes have been designed which are respectively applicable to the three separate phases of the preparation cycle in table tennis. Since this is the first implementation of aerobics in table tennis training, the presented programmes are meant to be executed once within the weekly microcyle framework. The examples of the aerobic programmes are constructed so as to substitute largely for classical activities and forms of training. Since aerobics allows for the accurate determination of training intensity, each work-out session can be precisely programmed according to the fitness of a team. It is also possible to change intensity during a work-out. Variations of intensity are produced by music rhythm changes or by changing the intensity of stepping (from high to low intensity and vice versa), with no substantial changes in choreography which is planned in advance.
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Proper Hydration in Table Tennis
Michael J. Scott
ITTF Sports Science Committee, United States of America
This oral presentation, although brief, will stress the importance of proper hydration in the sport of Table Tennis. athletes will be advised on the necessity of drinking fluids before, during, and after exercising. Adequate hydration can mean the difference between victory or defeat. More importantly, proper hydration can prevent muscular cramps, heat prostration, and hyperpyrexis.
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Disciplinary Problems Associated with the Former USOCDrug Testing Policy
Michael J. Scott
ITTF Sports Science Committee, United States of America
This brief lecture will demonstrate that in the past there was more than just an appearance of a conflict of interest in determining the disciplinary action taken against United States Athletes found positive for banned performance enhancing drugs. It is hoped that the same problems will not occur in the ITTF.
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Table Tennis for Persons with a Disability - The Current Circumstances and the Organization System -
Hitomi Minowa
The Japan Table Tennis Federation for the Disabled, Yokohama 231-0824, Japan
We have two classes of table tennis for Persons with a Disability at the Paralympic Games which are as follows:
1. Table Tennis for Persons with a Physical Disability 2. Table Tennis for Persons with an Intellectual Disability
Persons with a visual disability and persons who are hearing impaired have also managed their own championships at national and world levels. In Japan, after the Japan Table Tennis Association for the Disabled and the Japan Table Tennis Federation for Players with an Intellectual Disability were combined last year, the Japan Table Tennis Federation for the Disabled was established and became a full member of the Japan Table Tennis Association. This means that the Japan Table Tennis Federation for the Disabled is now connected with the International Table Tennis Federation through the Japan Table Tennis Association, which is a very significant development.
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Biochemical and Physiological Examination of Intellectually Disabled Table Tennis Players
K. Abe1, Y. Kawakami1, M. Ohuchi1, Y. Watanabe1, Y. Shibata1, S. Takahashi-Abbe2
1 Tohoku Fukushi University, Sendai, Miyagi 981-0943, Japan 2 Tohoku University Graduate School of Dentistry, Sendai, Miyagi 980-8577, Japan
In Japan table tennis is one of the most popular sports for the disabled as well as the non-disabled. Table tennis (including wheelchair and blind table tennis) is an official individual event of the 1st National Sports Games for the Disabled in Japan (in October, 2001). Blind table tennis is spreading independently in Japan. Players can enjoy the game as the equipment and the rules are modified in accordance with the characteristics of the disabilities. The table tennis is one of the sports that can pursue skill improvement. The table tennis event for the intellectually disabled was introduced into the Sydney Paralympic Games for the first time last year and the players participated from Japan. A table tennis strength-training camp including the Paralympic players with intellectual disability was held in Tohoku Fukushi University in last September; four men and four women players took part. We studied whether the practice of table tennis placed a big burden on the intellectually disabled. The following biochemical and physiological examinations were employed to assess the mental and physical conditions of players with intellectual disability: salivary cortisol, urinary 17-ketosteroid, urinary 17-hydroxycorticosteroid, the systolic blood pressure, the diastolic blood pressure, the heart rate, the centre critical fusion frequency etc.
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Rebound Characteristics of the New Table Tennis Ball - Differences between the 40 mm (2.7 g) and 38 mm (2.5 g) Balls -
Yuji Iimoto1, Kazuto Yoshida2 and Nobuo Yuza1
1 Chukyo Women's University, Obu, Aichi 474-0011, Japan 2 Shizuoka University, Otani, Shizuoka 422-8017, Japan
Key word: ball velocity, rotational frequency, diameter of ball, mass of ball
The International Table Tennis Federation changed the diameter of the ball from 38 mm (2.5 g) to 40 mm (2.7g) after the Olympic Games in Sydney, 2000. It is expected that this will change the playing style and the tactics. The purpose of this study was to clarify the physical characteristics of the rebound of the new ball just after the impact against a racket with pimples inward-reversed rubber. To measure ball spin a ball marked on its surface was shot against the surface of a racket, by a robot machine, downward at 35°from the vertical in a laboratory controlled at 25℃ and at 70 % relative humidity. The velocity of incidence just before impact against a racket ranged from 14.19 m/s to 14.71 m/s, with three values of spin forward, 120 rps (High), 60 rps (Medium) and 5 rps (Low). The contact was filmed at 9000 Hz with a high-speed video camera. To calculate the velocity of the ball, the distance traveled in the 50/9000 s from just before the collision and until just after was measured on a computer display, and the spin was measured by the time taken for one rotation. They were measured at least ten times for each experimental condition. As the incident rotational frequency was increased, the reflected frequency showed a progressively bigger decrement between the 40 mm and 38 mm balls; i.e. the decrement ratio of the rotational frequencies was bigger with the 40 mm ball than with the 38 mm. It is expected that it will be more difficult for players to spin the 40 mm ball than the 38 mm. In the experimental conditions of High and Medium spin, the reflection angle for the 40 mm ball was different from that of the 38 mm ball, but with Low spin there was no difference between the two balls. However, the restitution coefficient showed little difference between the two balls under any conditions.
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Kinematic and Kinetic Analysis of the Racket Arm during a Hard Forehand Counter-drive
Takeji Kojima1, Jyunichi Kasai2 and Youichi Iino1
1 University of Tokyo, Komaba, Meguro, Tokyo 153-0041, Japan 2 Waseda University, Mikashima, Tokorozawa, Saitama 359-1164, Japan
The purpose of the present study was to analyze kinematically and kinetically the motion of the racket arm during a hard forehand counter-drive. Three male and 3 female advanced table tennis players participated in the experiment. They were asked to hit crosscourt hard, and then continually hit several top spin balls from a ball machine beyond the table. The motions of the trunk, dominant arm and racket were filmed with two phase-locked cine-cameras. The coordinates of the markers attached to the subject's body were digitized with a motion analyzer, and then were reconstructed into 3D coordinates using a DLT method. Torques of the shoulder, elbow and wrist joints were determined using a link segment model and a free body diagram of the arm. The angular velocities of horizontal flexion, internal rotation and abduction at the shoulder joint were larger than the velocities of flexion and supination at the elbow joint immediately before and at ball impact. The peak torque of horizontal flexion at the shoulder was 40-60 Nm, followed in order by the torque of internal rotation and that of abduction. The peak torque of elbow flexion was 10-15 Nm, and was relatively small. The peak torques of palmar flexion and radial flexion were 7-15 Nm, and would be relatively large compared with their maximal isometric torque. However, a part of the torque might be exerted by connective tissues and/or bones because the wrist joint was near its end of the range of motion when the peak torques were observed.
These results suggest that large torque exertion around the shoulder joint is important for a hard forehand counter-drive.
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Differences in the Racket Movements between Flick Strokes against Backspin and Float Services
Kazuto Yoshida1, Yuji Iimoto2, Shuichi Hiruta3 and Shintaro Ando4
1 Shizuoka University, Otani, Shizuoka 422-8017, Japan 2 Chukyo Women’s University, Obu, Aichi 474-0011, Japan 3 Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-0814, Japan 4 University of Tsukuba, Tenodai, Tsukuba, Ibaragi 305-0006, Japan
The purpose of this study was to clarify the differences in racket movement between the flick strokes against backspin services and those against float services. Four top Japanese male players participated in this study. Each performed 5 forehand flick strokes against each of the two types of services, which were identified beforehand. Cartesian coordinates (X, Y, Z) and orientation angles (azimuth, elevation, roll) of the racket were measured by an electromagnetic motion sensor. The timing of the contacts with the server’s racket and the receiver’s racket was determined by sudden change of acceleration as measured by accelerometers that were attached to the end of the racket handles.
The results are summarized as follows: 1) The mean time from the initial movement of forward swing to contact with the ball on flick stroke for each subject was about 0.2s. 2) For all subjects, racket faces at the instant of ball contact against backspin services were 10-20 degrees more open than against float services. 3) The timing of the change of the racket face from close to open against backspin services for all subjects was around 0.4 s before the instant of ball contact. Against float services it was around 0.3 s before the instant of ball contact. 4) The upward velocity of the centre of the racket at the instant of ball contact against backspin services for all subjects was faster than against float services.
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A Comparison of the Table Tennis Capabilities of China and Sweden
Xuelin Cai, Jianjun Tang and Yuan Hua
Beijing University of Physical Education, Beijing, 100084, R. P. China
This paper compares the strengths of the Chinese and Swedish table athletes by analyzing the skills data of Linghui Kong and Guoliang Liu, and Waldner and Persson during the finals of the 45th WTTC and the semi-final and finals of the 27th Olympic Games. According to the data, the average serve-and-attack percentage of the Swedish team was 26.6%, and Chinese was 19.3%. This shows that the Swedish team was more aware of the value of serve-and-attack. In more detailed analysis, it was found that the average percentage of winning serves and attacks by the Chinese was 67.0%, compared to 58.1% by the Swedes; the Chinese were superior to the Swedes in this skill. A comparison of the serving, receiving and attacking percentages shows that the Chinese averaged 27.6% and, for winning serves and attacks, 40.1%. The Swedish team averaged 18.6% and 31.3%. Thus the Chinese were superior to the Swedes in serving, receiving and attacking. The Chinese players were skilled in various playing styles and were successful with winning serves. It shows that the serving power of the Chinese was a threat to the Swedes. In periods of extended play, Waldner and Persson averaged 50.9% and 51.8%, respectively, and 54.6% and 53.8% for winning serves and attacks. The Chinese players, Guoliang Liu and Linghui Kong averaged 44.7% and 54.1%, respectively, and 34.4% and 51.47% for winning serves and attacks. This shows that the Swedes were superior to the Chinese during periods of extended play, especially Persson. On the other hand, it shows that the ability of Chinese players during extended play was not as good. Guoliang Liu has made progress in the last two years in extended play ability; however, he was not able to play well during the two games because of this limitation. Linghui Kong played as well as the Swedes. Our conclusion from this study is that athletes who wish to succeed should improve their abilities for extended play and their skills in initiating attacks. Knowledge Construction During Competitive Interaction In Table Tennis
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Carole Sève French Table Tennis Association
This study analyses the activity of top level players during matches. Its purpose is to identify how knowledge is used and constructed during elite performance. The activity of three French national team male players was studied during matches of the World Cup held in France from October 25 to 29, 1997, and during the ITTF Pro Tour Final held in Paris from January 9 to 12, 1999. |