Tennis play simulator the research on psychomotor efficiency in tennis on the basis of locomotion movements

Abstract tennis play simulator the research on psychomotor efficiency in tennis

Our earlier research on psychomotor efficiency specific to table tennis (?apszo, 1998) has shown that the speed of anticipatory and orientation ball-hitting movements, anticipation, and the index of behavioural fluctuations tested in simulatory conditions strongly correlate with sporting results. On the basis of the findings, we have elaborated a computer diagnostic system (?apszo, 2002) which enables testing psychomotor efficiency in ball games on the basis of fundamental and specific movements in order to figure out the psychomotor predispositions for particular games. The system consists of a computer, a controller and a measurement station. The computer enables preparing the measurement tests, the controller controls the measurement station, which allows testing fundamental or specific movements in conditions specific to a particular game. In this paper we present the measurement system to diagnose the psychomotor efficiency in tennis on the basis of fundamental locomotion movements. The purpose of the research is to verify whether the psychomotor factors tested on the basis of these fundamental movements (which means that everyone can perform them), can be treated as a psychomotor predisposition for tennis. If the verification is positive, the proposed system can be used by coaches to test the degree of specific to tennis psychomotor talent of children who cannot play tennis yet but would like to practice the sport.

Introducción

Our earlier research on psychomotor efficiency specific to table tennis (?apszo, 1998) has shown that the speed of anticipatory and orientation ball-hitting movements, anticipation, and the index of behavioural fluctuations tested in simulatory conditions strongly correlate with sporting results. On the basis of the findings, we have elaborated a computer diagnostic system (?apszo, 2002) which enables testing psychomotor efficiency in ball games on the basis of fundamental and specific movements in order to figure out the psychomotor predispositions for particular games. The system consists of a computer, a controller and a measurement station. The computer enables preparing the measurement tests, the controller controls the measurement station, which allows testing fundamental or specific movements in conditions specific to a particular game. In this paper we present the measurement system to diagnose the psychomotor efficiency in tennis on the basis of fundamental locomotion movements. The purpose of the research is to verify whether the psychomotor factors tested on the basis of these fundamental movements (which means that everyone can perform them), can be treated as a psychomotor predisposition for tennis. If the verification is positive, the proposed system can be used by coaches to test the degree of specific to tennis psychomotor talent of children who cannot play tennis yet but would like to practice the sport. In a game of tennis motor behaviour has a character of sequential movements consisting of four separate, sequentially performed movements: preparatory movement, locomotion to hit the ball, ball-hitting proper, locomotion after ball-hitting. The sequence of such 4 movements can be called a sequential ball-hitting movement. The task of the preparatory movements is to optimise (rituals) the psychomotor state (?apszo, 1999), which is connected with the level of motivation, arousal and attention concentration and preparing the muscles (split step) to move the body towards the ball as fast as possible. The locomotion (displacement) to hit the ball is directed towards moving the body to the place where the ball is flying to reach the best position to hit it. Except for the service, the ball-hitting proper is performed with respect to the place, speed, spin and path of the ball’s flight and the position of the opponent. The final purpose of the ball-hitting proper is to win a point or cause the opponent to mishit the return. The aim of locomotion (displacement) after the ball has been hit is to reach the best position on the tennis court as quickly as possible to cover the possible lines of flight of the returning ball. The speed and the accuracy of sequential ball-hitting movements are related to the anticipation of coincidence (Belisle, 1963), which consists of predicting the time or the place (or both) where the opponent or the ball will arrive and performing a movement coincident with the time and the place. This anticipation can be divided into place and movement coincidence anticipation (?apszo, 1999). In the first case, the anticipation consists in predicting the place towards which the ball is moving and executing a displacement movement in order to approach this place. In the second case, the anticipation is responsible for the spatial and temporal coincidence of the act of striking the ball with the path of the moving ball. The place coincidence anticipation consists in prediction of the direction of the ball’s flight on the basis of the opponent’s ball-hitting movement proper or the early phase of the ball’s path. This information can be treated as an anticipatory stimulus, indirectly indicating the place towards which the player’s displacement movement should be carried out. The final phase of the ball’s path is the basis for the movement coincidence anticipation, and can be regarded as an orientation stimulus, directly indicating the exact spot and time of contact with the ball. The sequential ball-hitting movements can be initiated by anticipatory or orientation stimuli. The movements initiated by the anticipatory stimuli are called anticipatory ball-hitting movements. The initiation of these movements on the basis of orientation stimuli is characteristic of orientation ball-hitting movements. Place coincidence anticipation is based on memorisation of the way in which the ball was struck by the opponent and the place where the ball ended up. Memorised relationships of this kind make up an anticipatory schema (?apszo, 2000), the essence of which is similar to Schmidt’s motor schema (Schmidt, 1975). In this paper we present the construction, simulatory and diagnostic possibilities of simulator I, in which only the locomotion movements were performed. The movements have a character of fundamental movements for proper ball-hitting and can be performed by people who cannot play tennis. The movements are very important in a tennis game and sometimes are called “foot work” by coaches. The construction and diagnostic application of the simulator is based on the anticipatory model of human motor behaviour (?apszo, 2000), which contains the concept of human movements control (motor control) and psychomotor efficiency (?apszo, 1999), sporting aptitude and talent, efficiency profiles, types of ball-hitting movements and anticipation in racket games. Human movements should be treated as a psychomotor process, in which the mental (psychical) and motor systems are engaged. The mental system consists of the sensor and nervous systems, memory structures, information processes. The motor system is responsible for the execution of movements and supplying the muscles with energy. Both systems are connected by the senso-neuro-hormonal system. Psychomotor efficiency reflects the effectiveness of functioning of the mental and the motor systems and of the cooperation of the systems in the motor behaviour specific to a particular sport. The efficiency can be described in a general and a detailed way by the level of performance in different psychomotor tasks and by indexes calculated on the basis of the performance. In assessing the general psychomotor efficiency in tennis, the following factors can be measured (general factors of psychomotor efficiency): the speed of anticipatory (‘brain’ and ‘body’ speeds) and orientation sequential ball-hitting movements (‘body’ speed), the level of behavioural fluctuations (the capability of optimising attention concentration, motivation, arousal, resistance to disturbances), and the capability for anticipation and competitiveness. In the more detailed approach the following detailed factors of psychomotor efficiency, among others, can be measured: the components of the speed of anticipatory and orientation ball-hitting movements, i.e. the times taken for these movements to be initiated and executed, the speed of movements in different directions, the capability for anticipation of different ball flight directions, etc. The psychomotor efficiency can be estimated on the basis of psychomotor profiles (Skorny, 1974) that in presented study constitute graphs of measured speeds (times) and indexes calculated on the basis of the speeds. The graphs present the distribution of the speeds (times) and indexes in the same scale. These profiles can be divided into group and individual, general and detailed ones. The general profiles are created on the basis of the speed of all tested movements, while detailed profiles on the basis on the speed of particular movements. Sporting predispositions constitute such psychomotor factors which have a strong influence on sporting results. The psychomotor profiles describing the distribution of psychomotor predispositions enable the aptitude level for tennis to be estimated. A very talented player is a person whose predispositions for tennis are at a very high level though not necessarily at the top level. Cluster analysis (Lapszo, 1998) can be used to classify players with respect to their level of aptitude for tennis.

Tennis play simulator I – Construction and simulatory possibilities

The tennis play simulator, in versions I and II, consists of the simulator proper, a controller and a computer. Version I is designated to test psychomotor efficiency specific to tennis on the basis of fundamental movements, while version II (?apszo, 2006) enables testing the efficiency on the basis of specific movements. Consisting of 12 stimuli boards, a set of sensors, allows tennis play conditions to be simulated (Fig. 1). There are 14 lamps on the stimuli boards (anticipatory stimuli) that simulate the spot where the ball is struck by one’s opponent. The lamps in the ten sensors (orientation stimuli) indicate the spot where the simulated ball is to be struck by the subject. Programming enables different directions and speed of the ball’s flight to be simulated by constant pairs of lamps on the board and in the sensors which are switched on sequentially. The interval between the switching on of the lamp on the board and that in the sensor determines the speed of the simulated ball’s flight. Up to 14 ball-hitting movements can be simulated. In this version of the simulator the simulated forehand or backhand strokes were not performed. We have tested only the locomotion movements for these strokes. The subject’s task was to touch the flat plate of a tactile sensor with the inside (forehand) and outside (backhand) of the hand (simulation of touching the flying ball instead of hitting it in a real play). There was electronic identification of the reaching position to initiate the simulated ball-hitting (the final target of the tested movements). A single locomotion movement to hit the ball, a series of the movements, or play for points can be simulated.

Fig. 1. The proper tennis play simulator I (with tactile sensors).

The anticipatory locomotion movements to ball-hitting were stimulated by 14 constant pairs of lamps (one on the board and another one in the sensor), which constitute the anticipatory schema. In this study the following anticipatory schema was created (Fig. 1): (1-10),(2-3),(3-6),(4-8),(5-5),(6-9),(7-10),(8-2),(9-3),(10-11),(11-9),(12-7),(13-4),(14-2). Other anticipatory schemas can also be set up. It is also possible to locate the anticipatory stimuli (lamps on the board) in freely chosen places on the opponent’s side of the court. One can also alter the location of the sensors, and their height and inclination. The break between switching on the lamps on the board and the lamps in the sensors (a simulated time of the ball’s flight) was from 0.5 to 1.5 seconds and depended on the simulated length of ball’s flight (distance between the lamp on the board and in the sensor). The memorising of the anticipatory schema allows the place (sensor), which should be reached by player to be predicted on the basis of switching on the lamp on the stimuli board. The orientation locomotion movements to ball-hitting were stimulated only by the lamps in the sensors. The tactile sensors identified the instant of reaching (touching the sensor) the spot where the ball should be hit. The speed of anticipatory and orientation locomotion movements was timed in seconds from the instant the lamps in the sensors were switched on. The simulator enables the following freely-chosen factors/parameters to be simulated: the spot where the opponent hits the ball, the ball’s flight line/direction and speed, the spot (target) which should be reached by subject and the number of simulated locomotion movements in a rally (test). The simulator also permits the simulation of play for points with the tennis system of scoring points. The play can consist of any number of sets. To score a point all the simulated strokes in a rally have to be performed in a limited time. This time limit is realised by altering the break between the switching on of the lamps on the board and in the sensors (the speed of the simulated ball’s flight) and by limiting the time the sensor has to wait to be touched (touching the ball). The speed of the simulated ball’s flight can be altered, so the subject can be made to play against a simulated opponent who plays faster or slower. 6 female and 6 male students of a tennis coach course at the Academy of Physical Education and Sport in Gdansk, 5 younger juniors and 5 juniors practising tennis in the Sopot Tennis Club participated in the experiment. The average age of male students was 23.6 years, female students 22.8 years, younger juniors 14.8 years, juniors 17.2 years.

Diagnostic possibilities of simulator

Anticipatory and orientation locomotion movements to ball-hitting The subject’s task was to perform locomotion movements to the places indicated indirectly by the lamps on the board (anticipatory locomotion movements) or directly by the lamps in the sensors (orientation locomotion movements). The time (in seconds) elapsing from switching on the lamp in the sensor to the instant of touching the sensors was the measure of the speed of particular movements. Accordingly, the shorter the measured time, the higher the tested speed. The speed of anticipatory and orientation locomotion movements was investigated in series (tests) of 11 different movements. The result of the whole test was the average speed of these 11 measurements. The experiment lasted for 3 days. On the first day 6 different tests of anticipatory movements were used. On the second day the experiment consisted of 4 tests of anticipatory and 4 tests of orientation movements. On the third day the subjects played for points. The results of the last 3 tests obtained for each kind of movements were then averaged in order to obtain the final speed of anticipatory (Ta) and orientation (To) locomotion movements to ball-hitting. The curve of anticipatory schema learning Learning curves were used to investigate behavioural fluctuations (?apszo, 1998). These curves illustrate the process by which the anticipatory schema develops. A test of the speed of anticipatory locomotion movements was used to investigate the anticipatory schema learning process. This test was repeated 10 times until the measurements stabilised. The results obtained were approximated by the exponential learning curve. The following formula of this curve was used: T(p) = (Tmax – Tp) x (1 – It)(p – 1) + Tp, where p – serial number of the trial, T(p) – the result of the test as a function of the trial, Tmax – the lowest speed of anticipatory ball-hitting movements, It – increase in learning (memory) in each trial (computed), Tp – potential speed (the asymptote of the learning curve, computed). The changes in attention concentration, motivation and arousal produced a scatter of test results around the learning curve. The statistical parameter R2 showing the magnitude of this scatter was used as the index of behavioural fluctuations If (?apszo, 1998). If R2 = 1, all the test results lie on the learning curve. The index of place coincidence anticipation The increase in the speed of locomotion movements resulting from the place coincidence anticipation was treated as an index of this anticipation (Ia). Place coincidence anticipation is based on the association of the position of the sensor with a definite lamp (anticipatory stimuli) on the stimuli board. The speeds of the anticipatory (Ta) and orientation (To) locomotion movements to ball-hitting were used to calculate the Ia index according to the following formula (?apszo, 1998): Ia =(To – Ta) /To. This shows the extent to which the speed of displacement to the place towards which the ball is flying increases as a result of place coincidence anticipation. If Ia = 0.1 the increase in the Ta as a result of ball’s flight spot (place coincidence) anticipation was 10 %. The simulated play for points – the index of capability for competitiveness The simulator enables playing for points. Programming the defined speed of play (ball’s fight speed) for a series of, for example, 5 movements can be scored if the subject performed all 5 movements with the required speed or not. Too late locomotion in one of the 5 movements causes losing the point. The program of the simulator allows scoring the points in the tennis system. The game can be conducted in a programmed or stochastic way. In the second case even the person conducting the research does not know how the game is going to proceed. In the experiment with playing for points only juniors and younger juniors participated. The game was conducted to win one set. The ratio of the number of lost to won games multiply by the coefficient of simulated play speed (the speed of ball’s flight) was treated as an index of capability for competitiveness (Ic). The play for points can be used to diagnose the general ability for competitiveness (selection of children for tennis) or readiness for a particular match or tournament and to improve the speed of locomotion movements on the basis of the “starting method” (training process). The simulator enables controlling the score of the play by increasing or decreasing the speed of the required play. The simulated play for points enables practising the speed of “foot work” in competitive conditions, in which the level of motivation is usually higher than in practise conditions. The index of psychomotor efficiency In order to describe psychomotor efficiency in a comprehensive way, the index of psychomotor efficiency Ipe was introduced. The index was calculated on the basis of the following formula Ipe = (If + Ia+ Ic)* 5/(Ta + To). The index expresses the speed of anticipatory and orientation motor reacting and a capability for psychomotor state optimising, anticipation and competitiveness and it can be used to estimate comprehensively the psychomotor efficiency of tested children, who can not play tennis and also advanced players in every moment of the training process.

The results and discussion

The obtained results are presented in form of group and individual profiles (Fig. 2 a,b), The profiles enable comprising the groups, groups and players, and particular players profiles.

Fig.2. The group (a) and individual profiles (b) of psychomotor efficiency for the tested groups and freely chosen players from the groups.

Index Ic is presented in Fig. 2 only for junior groups because the female and male students did not participate in the play for points session. For this reason index Ipe shown in Fig. 2 was calculated without index Ic for all groups. Index If is greater than 0.75 (the lower limit of the occurrence of learning) in all male groups. This implies that male students and juniors are able to learn anticipatory behaviour. The fluctuations in attention concentration, motivation and arousal (behavioural fluctuations) are smaller in the male group than in the group of less skilled female group (0.84>0.67, less dispersal). These results are in accordance with Nettleton’s (1986) research, which indicated the differences in attention flexibility between more and less skilled athletes in fast ball games. Male players displayed a much higher speed in both kinds of locomotion movements (Ta, To) and a greater capacity for anticipation (Ia) than female players. The speed of anticipatory and orientation ball-hitting movements was lower in the older group (not regularly practising tennis) than in the younger one (regularly practising tennis) by 10% (Ta) and 20 % (To) respectively. The average index of anticipation was 20.5% for older groups (students) and 14% for younger (juniors) groups. The differences in the speed of locomotion to ball-hitting and anticipation are probably due to age, frequency of special training, and the sporting experience. These findings are in disagreement with those in published studies, in which the reaction and movement time (Keele, 1982) and anticipation (Meeusen, 1991) were found not to differentiate between highly proficient and less skilled players. The highest index of psychomotor efficiency was obtained by the male students (1.80), a similar younger juniors and juniors (1.74, 1.7), the lowest one by female students (1.24). In the research with simulated play for points only the group of younger juniors and juniors participated. The younger juniors showed a higher level of readiness (0.54) for competition than juniors (0.68) at the time when the study was conducted. 1.1.1.1 Psychomotor predisposition, profiles and aptitude for tennis The general factors of psychomotor efficiency, i.e. the index of behavioural fluctuations (If), the speed of anticipatory (Ta) and orientation (To) locomotion movements to ball-hitting and the index of place coincidence anticipation (Ia) and capability for competitiveness (Ic; children) or readiness for competition (players), psychomotor efficiency (Ipe) obtained in this study were used to figure out the psychomotor predispositions for tennis. These general factors were correlated with the sporting ranking of the tested groups. The obtained correlation coefficients are presented in Tab. 1.

Table 1. The correlation coefficients of the tested factors with sporting results for the examined groups.

The research has shown that all the tested psychomotor factors correlate with the sporting results for all groups and, owing to that, they can be treated as psychomotor predispositions for tennis. In order to examine the degree of aptitude for tennis, the method of psychomotor profiles is proposed. These profiles make up a graphic presentation of general psychomotor efficiency factors (psychomotor predisposions) for the tested groups and/or players on the same scale. The presentation of the research result in form of profiles can be more friendly for coaches and players. The profiles for tested groups (Fig. 2a), freely chosen players from the groups (Fig. 2b) are presented in Fig. 2. The absolute and relative differences in psychomotor profiles can be calculated. The differences between profiles of players can be analyzed with respect to age, sex, level of skills, method of practice, tactics of play, etc. In order to investigate the strong sides and the type and level of psychomotor weaknesses of particular groups or players, a master profile can be elaborated. The analysis of psychomotor profiles can be particularly useful to choose the most talented children, who want to practice tennis and to steer the training process to improve weak sides of psychomotor profiles of players on the every stage of practice process.

Conclusions

• The research presented in this paper using the tennis play simulator I has demonstrated:
• The differences in all general psychomotor efficiency factors between tested groups;
• The highest level of psychomotor efficiency in a group of highly skilled players;
• That the general psychomotor efficiency factors can be treated as predispositions for tennis;
• That profile analysis can be used to assess the psychomotor aptitudes for tennis;
• That the type and magnitude of psychomotor deficiency of advanced players can be recognised on the basis of group and individual psychomotor profiles.

The presented study has shown that the tennis play simulator I seems to be useful for researchers and coaches to test the psychomotor efficiency specific to tennis on the basis of fundamental movements that can be easily performed by people (children) who cannot play tennis. The simulator can be used to select very talented children for tennis. It can also be useful to test the psychomotor efficiency profiles and practise the speed of locomotion movements of advanced players without any interference on the technique of the strokes.

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