The effect of different exercises on the characteristics of the strength-time curve of the skill of crushing serve in volleyball

Abstract

   As a result of the development in the skillful performance in this game, experts and trainers sought to find means and training methods to develop this skill. Hence the importance of the research lies in the fact that differentiated exercises help the player to perform movements under changing and different conditions, so that the player is able to confront the various circumstances and situations that he is exposed to. It has during the game and well, as well as the development of the strength-time curve values of the player, to reach the best biomechanical conditions and thus the development of the overwhelming serve, and the research problem was through the researcher's observation of the kinetic analysis of the overwhelming service skill of some teams and specialized centers for youth that there is a weakness in the performance of the serving player During the stages of skill, specifically the stage of pushing, and this is due to the failure to adopt the correct position of the fulcrum, which causes a loss of balance and increases the amount of effort exerted during the approaching stage, and this may be a result of a weakness in the internal strength represented by the strength of torque of the parts of the body involved in the performance of the two moments of fulcrum and pushing causing mechanically unwanted bends in the relative angles of the knee joint, so the researcher decided to study this problem through physical analysis Mechanics for the crushing serve and the development of divergent exercises that would raise the level of muscle strength and the level of skill towards the best, while the research objectives are to prepare differentiated exercises to develop the force-time curve to develop the skill of the crushing serve in volleyball. As for the research method, the researcher adopted the experimental approach by designing the two equal groups (experimental and control ), the research community included young players in the specialized center for volleyball in the district of Shatra, whose ages ranged from 16-18 years for the season (2020-2021), who represent the youth category and their number is (20) players, (6) players were selected for the reconnaissance sample. (14) players representing the research sample and by (70%) of the original community. One of the most important conclusions is that the use of differentiated exercises gave a clear picture of its preference over the traditional program, through the results shown by the experimental group and its preference over the control group.