Basic motor abilities: Predictive value on the situational test results in 12-14 years old soccer players

Introduction

In soccer, guidance and selection of candidates, as well as tracking transformational effects during the exercise process and training itself, knowledge of primary stability of the motor ability is indispensable. Besides, it is also important to know which of these most significantly affect the improvement of results in tests of situational motor abilities. The explanation of this issue within this research is reflected in the scientific significance of the present paper. Soccer requires a high level of adopted motor structures for solving certain specific tasks that occur during the game at the phases of defense and attack. For these reasons, players must be able to demonstrate the maximum level of their motor abilities (speed, explosive strength, coordination, etc.) before the game, i.e. to react in the most appropriate manner in an unforeseen situation that they may encounter. Technical preparation of soccer players is a fundamental performance prerequisite enabling players’ physical fitness attributes to be fully expressed in game-related tasks. We emphasize that further progress in terms of technical improvement of players, which is especially important at this age, is not possible without parallel work on development and maintenance of motor skills that are vital to the soccer game [7, 8, 10].

The main goal of this research was to determine the impact of the predictive set of variables (basic motor ability) against the criterion set of variables (situational motor ability). It was particularly important to determine which of the applied basic motor variables had the greatest value in this respect. The reason we investigated this issue was to achieve good results in soccer depending on basic motor ability [6] in the view of the potential for progress at this age, as well as to define indication of future achievement.

Materials and methods

Samples
The test sample in this survey were the students of school clubs FC ”Sloboda“, FC ”Tuzla“ and FC ”KLUB-7“ based in Tuzla, of 12-14 years of age. The students of all three soccer schools were members of the pioneer competition selection in the above mentioned soccer clubs.

All participants had undergone regular physical examination, which is standard procedure and means that all children were clinically healthy without any visible manifestation that could significantly affect the test results. The average age of the respondents ranged within 13±1 years.

78 players from the above mentioned clubs entered the total sample of respondents for this survey. The basic criterion for entering the model was that the respondents were students of the same soccer school i.e. that they did not come from another club in the previous year.

Experimantal Procedure
Basic- and situational motor abilities were tested at the stadium of NK ''Tuzla'' in Tuzla. All tests were carried out in the afternoon, according to the time frame of a regular training. Before the testing, ten minutes of warming up was carried out with the respondents to prepare them for testing and was led by trainers who work with children.

Variables
Within this study, 15 tests were used to assess the basic motor skills that represent a set of predictor variables belonging to the individual segments for measuring motor space, and defined as measures to assess the segmentary speed, explosive strength, coordination, flexibility and balance.

To estimate the movement frequency factor (segmentary speed) the following tests were used: MBFTAR – hand tapping, MBFTAN – leg tapping, MBFTNZ – leg tapping against wall.

To assess the flexibility factor the following tests were applied: MFLBOS – side legs wide spread, MFLPRK – adapted Kraus-Weber floor touch test, MFLISK – slewing with bath.

To assess the explosive strength factor the following tests were applied: MESSDM – standing long jump, MESTRO – standing triple jump, MES20V – 20 m sprint.

To assess agility the following tests were applied: MAGKUS – side steps, MAGONT – ground agility, MAGTUP – zig-zag test.

To assess the balance ability the following tests were applied: MBAU2O – standing upright on both legs with eyes open, MBAU2Z – standing on both feet on the balance bench with eyes closed, MBAP2Z – standing on both feet sideways on the balance bench with eyes closed. Tests and measurements of basic-motor abilities were obtained on the basis of tests carried out in Kurelic and associates’ research [4].

The sample of criteria variable represents a group of nine (9) measuring instruments, which cover an area of a larger number of latent dimensions that are important for success in soccer.

Each situational motor dimension is covered with at least three situational motor variables. For the evaluation of situational precision the following measurement instruments were used:

SPPNVM – foot preciseness in a straight line – vertical goal (ball at standstill) – The task is performed outdoors or indoors, minimum dimensions of 30 x 5 meters. The respondent is 20 meters away from the goal and 5 meters away from the ball, which stands at 15 meters from the goal. At the goal we allocated a three-door set with flags of 120 centimeters in height, so that the middle door is 1.5 meter in size and the doors on both sides of the central door are 1 meter in size. The respondent moves toward the ball that rests at a distance of 15 meters from the goal, and hits the ball trying to achieve the maximum point. The task is performed 10 times. Rating: a hit in the middle door = 3 points, a hit in the side doors = 2 points, a hit over and beside marked doors = 1 point. If the ball hits the rack and returns, the result is worth less, if the ball rebounds off the flags into the area of better results, it is worth a better result.

SPPNVK – foot preciseness in a straight line – vertical goal (ball in movement) - The task is performed outdoors or indoors, minimum dimensions of 30 x 5 meters. The respondent is 20 meters away from the goal, leads the ball with at least two contacts before the 15 meters line, and hits the ball, trying to reach the maximum number of points. The task is performed 10 times. Rating: a hit in the middle door = 3 points, a hit in the side doors = 2 points, a hit over and beside marked doors = 1 point. If the ball hits the rack and returns, the result is worth less, if the ball rebounds off the flags into the area of better results, it is worth a better result.

SPENVM – elevating foot preciseness – vertical goal (ball at standstill) - The task is performed outdoors or indoors, minimum dimensions of 30 x 5 meters. The respondent moves from within 15 meters’ toward the ball, which is placed 10 meters from the goal, and shoots at the goal. The task is performed 10 times. Rating: direct hit into the goal = 3 points, hit into the goal with the ball that rebounds off the ground = 2 points, goal scored out = 1 point.
To assess the ability of handling the ball the following measurement instruments were used:

SBLHOZ – horizontal bouncing of the ball against the wall for 20 seconds - The task is performed outdoors or indoors, minimum dimensions of 3 x 3 meters. A 2 x 2 m square is drawn on the wall, and a 2.5 x 2 m rectangle is drawn on the ground . At the cue “NOW“ the respondent hits the ball so that it must always come back behind the 2.5 m line after rebounding off the wall. The task was completed after 20 seconds expired. Each shot properly made was rated in a time frame of 20 seconds. The task was performed five times.

SBLUPO – hitting the ball against the wall after it has bounced off the base - The task is performed outdoors or indoors, minimum dimensions of 3 x 3 meters. A 2 x 2m square is drawn on the wall, and another 2 x 2m square is drawn on the ground. The respondent hits the ball against the wall so that it hits the ground after each rebound; after it bounces against the ground the respondent hits the ball again in the air toward the wall. The ball is allowed to land only in the distinct 2 x 2m square. Each correctly performed strike brings 1 point. The task is performed five times. The task is interrupted and we determine the number of points up to the end, under following circumstances: if the ball gets out of the square, if the ball rebounds two or more times off the ground, if the respondent strikes the ball before it bounces off the ground, or if the ball strikes out of the 2 x 2m square.

SBLVSL – leading the ball in a slalom - The task is performed outdoors or indoors, minimum dimensions of 15 x 5 meters. The dribble path is marked by the start line which is also the target line 1 meter away from the first flag, while the other flags are placed at every 2 meters. Flags are 150 centimeters high. At the cue ”NOW“, the respondent starts right toward the first flag, passes it and leads the ball toward the second flag which he passes from the left. The respondent conducts the slalom by passing the last flag and returning while leading the ball around the flags in the same way. The task is completed at the moment when the player and the ball pass through the target line. The time is measured in tenths of seconds. The task is repeated five times, and all results are entered into the measurement list. The respondent must correctly pass by the flags; in case of a mistake the respondent has to go back and pass between the flags correctly.
To assess the ability of dribbling speed the following measurement instruments were used:

SBRVPO – fast dribble in a semicircle - The task is performed outdoors, minimum dimensions of 25 x 15 meters. At the cue ”NOW“, the respondent leads the ball outside the circle 9.15 m in diameter, watching not to step on the line of the semicircle either with the foot or the ball. When the respondent passes the extended line of 2 meters in length, he returns dribbling the ball again after the semicircle until he passes with the ball over the finish line marked by two flags, which are at a distance of 2 meters. The task is completed at the moment when the player and the ball pass the finish line. The time is measured in tenths of seconds, from the cue “NOW“ to passing through the finish line. The task is repeated five times, and all the results are entered into the measurement list. If the respondent steps on the line of the semicircle, or does not pass with the ball the extended line of the semicircle, or does not pass with the ball over the 2 m finish line, the task must be repeated.

SBRV20 – fast dribble for 20 m from a standing start - The task is performed outdoors or indoors, minimum dimensions of 20 x 5 m. At the cue ”NOW“, the respondent dribbles up quickly so that he hits the ball once again within the distance of 3 meters and touches the ball at least three times in the next 17 meters, and passes with the ball through the finish line. The time is measured in tenths of seconds, from the cue “NOW“ to passing through the finish line. The task is repeated five times, and all the results are entered into the measurement list. The ball must be hit at least five times within the 20m track.

SBRVPU – fast dribble with change of direction at an acute angle - The task is performed outdoors or indoors, minimum dimensions of 20 x 10 m. At the cue ”NOW“, the respondent dribbles as fast as he can, passes around the flags changing direction of the movement at 900 and passes through the finish line. The task is completed at the moment when the player and the ball pass the finish line. The time is measured in tenths of seconds, from the cue ”NOW“ to passing through the finish line. The task is repeated five times, and all the results are entered into the measurement list. The flags are 150 centimeters high.

Statistical Analysis
Values are presented as mean values and SD. For the purposes of this research in accordance with the set aim of this study, we used factor analysis and multiple regression analysis. Factor analysis was used to determine factorization variables of the situational motor ability in order to come to a general situational motor factor. Regression analysis was used to determine the impact of the predictive system of variables (basic motor ability) on the criterion. The significance level was established at p< 0.05.

Results

Central and Dispersion (Variance) Parameters
Based on variability parameters, i.e. the relationship between the arithmetical mean and standard deviation, we can see that the variability found in the following variables from the basic motor ability is increased: MFLPRK - forward band on stand, MBAU2O – standing upright on both legs with eyes open MBAU2Z – standing on both feet on the balance bench with eyes closed, MBAP2Z – standing on both feet sideways on the balance bench with eyes closed.

From the extent of variables for the assessment of situational motor ability in soccer players, increased variability is present at the following variables: SBLHOZ – horizontal bouncing of the ball against the wall for 20 seconds, SBLUPO – hitting against the wall after the ball has bounced off the base, SBLVSL – leading the ball in a slalom.

We tested normality of distributions upon the parameters of Skewness and Kurtosis. Based on the obtained results, we see that the parameters of Skewness (which tests asymmetry of the distribution of results) for all applied variables are within the normal range. Based on the parameters of Kurtosis (which tests elongated or flattened distribution of results), we can see that the expressed value of this parameter is present only in variable MAGTUP – zig-zag test (6.90) indicating that the results are highly concentrated around the arithmetic mean.

Based on the obtained results, it can be concluded that the arithmetic means in the applied variables of basic motor and situational motor abilities are the real representatives of the treated variables, which may be representative for this sample of respondents.

Inter-Correlation of Applied Situation Motor Variables
Based on the results obtained for the inter-correlation matrix of the applied situational motor variables, we can see that all the correlation coefficients between the applied variables are statistically significant.

Factor Analysis of Applied Situational Motor Variables
Situational motor variables were subjected to factorization with the application of Guttman–Kaiser criterion. Based on the calculated characteristic inter-correlation matrix equation by the application of Guttman-Kaiser criterion (Table 3), characteristic root was obtained, which explains (Cumulative %) 59.09 % of the common variance.

Based on the results (Table 3), we see that the projection of manifested variables vector on isolated factor is within -0.461 to 0.891 limits. With regard to the results thus obtained, this isolated factor can be defined as the general factor of situational motor abilities in soccer.

Regressive Analysis of the Criterion Variable of Situational-Motor Abilities in Manifested Space of Basic Motor Abilities
Based on the results (Tables 5 and 6), motor abilities explain 75% of total situational motor abilities (p<0.01). Four of fifteen variables (Table 7) have a statistically significant partial influence on the variable criteria, and these are the following variables: MBFTAN – leg tapping, MFLBOS – side legs wide spread, MES20V – running 20 m (sprint), MBAU2O – standing upright on both legs with eyes open.

Discussion

At is can be seen from the obtained results, the entire system of predictive variables is significant in prediction. It is clearly visible from the results that variables MBFTAN – leg tapping and MES20V - 20 m sprint from the high start, have a statistically significant individual influence on the criteria. We deem that segmentary speed and explosive strength cannot be viewed separately because they are correlated and largely depend on each other [11]. There are many reasons why these variables are shown as significant predictors and it is impossible to cover them all. However, we will mention those that we consider to be primary within this research. One of the reasons probably lies in the structure of situational motor tests used in the criterion set of variables, because the forms of movements are such that require fast and explosive moves and direction changes with or without the ball.

We believe that young football players resolve all technical-tactic tasks set before them on the basis of speed and explosive strength [2]. Other authors came to similar results in their research [8, 10]. Regarding the variable to assess flexibility MFLBOS - side legs wide spread, we think that the optimal level of flexibility contributes to the proper performance of the technical elements in soccer. This can contribute to the result improvements in situational motor tests, so that errors occurring during the execution of any technical element in soccer are minimized to the smallest possible measure thus contributing to faster test performance.
As for balance, we have to emphasize that in the performance of situational motor tests which were used in the criterion set of variables, balance position was disturbed. Efficient performance of situational motor tests requires correction of balance position [9].

From these results it is clear that the improvement of the results in the criterion, i.e. in the test of situational motor abilities, depends precisely on such motor structure which is primarily determined by segmentary speed, explosive strength, flexibility and balance.

We have to emphasize that generalization of the results obtained within this research is possible: primarily on those populations that have the same characteristics as the respondents in this survey, the results can only be generalized on those segments of anthropological space that are included in the variables sample.

Conclusions and Practical Application

We believe that this paper can contribute to safer and more efficient planning and programming of training with young soccer players, because the results of our tests helped us detect the basic motor abilities that are predominantly responsible for the success of the performance of situational motor abilities. Therefore, we will provide suggestions that in our opinion can improve the training process:

Training content which in its structure contains exercises of acyclic character should be represented in the training process because they largely contribute to the development of cognitive abilities (above all perceptive), which is very important for young soccer players; then, training content of soccer aerobic, exercises for leg work and for general movement technique, all in the function of optimal development of young soccer players. These exercises will certainly contribute to the development of specific coordination in young soccer players.
We are also of opinion that further advancement of technical preparedness is not possible without parallel development of basic motor abilities.
In this study there were detected the abilities of most influence on improving results in tests of situational motor abilities; such information can contribute to selecting the training assessment that would apply to working with young soccer players.

At the end we have to say that excellent success is only possible if the athletes’ preparation process and sport itself are based on scientifically founded tendencies, and this is probably the only and the right way in guiding our league competition towards contemporary attainments of the soccer game.