Antropomotoryka nr 51 - Akademia Wychowania Fizycznego w ...

Adam Kawczyński, Dariusz Mroczek, Jan ChmuraIntroductionThe ability to maintain psychomotor performance duringthe game is one of the most important ways to succeedin sport competition [1]. In the specialist literaturepsychomotor performance includes following components:movement time [2], reaction time [1], choice reactiontime [3], other cognitive tasks, i.e. visual search[4], motor skills, i.e. running speed [1]. Optimizationand developing of those skills require reliable and validmethods to asses and monitor through training process.Therefore we concentrated on movement time (MT) assessmentduring the game.Most of studies are made in laboratories (treadmillor bike ergometer) and focused on the effect of exerciseon components of psychomotor performance.Literature analysis clearly shows that psychomotorstudies in majority were made post-exercise [5, 6, 7,8]. It seems to be important that physiological status ofsubjects during the post-exercise tests is not identicalwith their status during the exercise, moreover exerciseintensity can influence test results [9, 4]. On the otherhand, only during competition and training the participantsare required to perform activities on moderateand high intensities, speed and accuracy [1] what substantiallyaffects athletes’ motor skills (2).It is well-known fact that during sport competitionsplayers are under pressure of numerous influences.Fatigue, which increases during the game, competes withability to maintain movement time; other components ofpsychomotor performance cannot be also disregarded.In widely accepted definition, fatigue is regarded asa psychophysiological state which appears during theeffort and contains two main components: 1) metabolicchanges in working muscles limiting the performance[11]; 2) central nervous system fatigue which affects motorand perceptual processing; both of them are extremelyimportant in high level ball game participation [12, 13].All facts showed above lead to conclusion thatimplemented method, which is performed during thegame, is an important step in sport science. Therefore,the aim of this study is to assess MT of elite volleyballplayers during the game.Materials and methodsSubjectsFourteen elite volleyball players, the members of PolishNational Junior Team, participated in the study. Theaverage age of participants (mean ± SD) was 18 ± 1years, the average height was 196 ± 7.39, the averageweight was 84.07 ± 7.77. Informed consent was obtainedfrom each subject. All the participants gatheredtogether at preparation camp before the 2009 FIVBBoys Youth Volleyball World Championship, Jesolo-Bassano del Grappa, Italy. The study was approved bythe local ethics committee.Blood lactate concentrationBlood sample was taken from the ear lobe for determinationof blood lactate concentration using portablelactate test analyzer (Lactate Scout, SensLab GmbH,Leipzig, Germany). Blood lactate concentration wasmeasured during the pre-game test and during the sets1, 2, 3 and 4.Measurement of movement timeThe research was done with the help of Optojump system(Microgate, Bolzano, Italy), which measured footcontact time with the ground in a measurement areawith the precision up to 0.001 s. Among the advantagesof this device the most important is possibility to adjustthe software to the needs of participants and the placementof working measurement areas in different locationsdepending on the specific trial. This useful toolenables to develop a test for measurement of movementtime.Before pre-match warm up all players were instructedin details about the experiment procedure and locationof measurement devices (Fig. 1).During the pre-game test, game effort and each ofthe four sets played, all participants had to follow identicaltest procedure, according to which the player tookhis place in the starting square located on the base lineof the court (Fig. 1). The trial began in a square of side70 cm, within which the start position was free. Subjectstood with his foot staggered, where either the left orright leg was forward. The setting allowed for placementof backward leg so that the heel of the feet wasalways in the measurement area of the first couple ofthe Optojump measurement device (10 cm measuringfrom the tuber calcanei). The tested player stood facingthe net, on which a light source was located at theheight of 243 cm, directly in front of him. Reacting to thesignal (stimulus), he had to run as quickly as possibletowards the light. In order to prevent anticipation of thestimulus, the signal was given irregularly. The intensity– 26 –