Sciences Journal Of Physical Education

Abstract:
The study aimed to identify the values of the biomechanical variables of the four stages (approach, rise, hitting, landing) in the skillful performance of the wavy serving skill of jumping by volleyball.
The researchers used the descriptive approach in the method of associative relations which is appropriate to the nature of the research problem. The researchers identified the research community and they are players of Al-Rumaitha sports club volleyball team (10) players were given to each player three attempts, to have (30) views are subjected to analysis and the best score was chosen. The test was shown to a group of experts. As for the biomechanical variables, the researchers used a camera type (CASIO) with a frequency speed of 300 images / s to extract the biomechanical variables. The researchers used kinovea (0.8.24) kinetic analysis program to extract the values of the biomechanical variables. The most important conclusions are that the distance of the implementation of the transmission in the first stage until the stage of ascension greatly affect the degree of perfect angles of the joints that allow to take the good technical situation, the more appropriate angles whenever the shape of motor in the best case. , And the increase in the degree of knee joint leads to increase the starting angle and maximum flexion of the trunk arc and the height of the hip point at the moment of hitting the ball.

The aim of this research is to identify the effect of exercises in the style of competition on some hormones , like (TSH, T4, T3) and the variables in the immune system in the blood(i.e. the total number of white blood cells, neural cells, acid cells, basal cells, lymphocytes and single- core cells) for the flying feather category of players who are under 17 years.
The researcher uses the curriculum demo on a sample which consists of (6) players who represent the National Iraqi team of flying feather for the category of players under 17 years. In addition, he uses the means and the tools for gathering information as: scientific sources syringes, pipes, a box for drawing, collecting and saving blood, electroscope to analyze the hormones. The researcher reached to a number of conclusions and they are as follows. First, there is a negative impact of the effort exercises in the style of competition on some variables in the immune system in the blood(i.e. the total number of the white blood cells, neural cells, acid cells, basal cells, lymphocytes and single- core cells) of the flying feather players. Furthermore, there is a positive impact of the exercises in the style of competition, on some blood hormones (T3, T4, TSH) for the flying feather category of players under 17 years.
The recommendations are: adopting the results of the research and make use of them in recognizing the variables in the immune system that take place before and after the exercises in the style of competition, as well as, adopting the results of the research and make use of them in knowing the functional indicators (hormones) before and after the exercises in the style of competition