شبكة المعلومات العربية التربوية

The problem of the study is exemplified in the research question set fourth by the researcher as follows: Is the height of the jump higher when the players jumps from the ground based on the sole activity of the front thigh muscles when compared to the jump height the player can achieve when performing a preparation jump for the main jump? The researcher attempts to approach the problem by measuring the (EMG) of the muscles of the legs in players during their performance when jumping from two heights on a platform in order to measure the neuromuscular activity (electrical activity of the of the muscle through the EMG device) in order to find the highest value of the electrical activity of the muscle membrane and its relationship to the highest height of the jump as well as to identify the relationships between the highest value registered via the EMG with the highest height after deep jumping from the height of (15 cm and 30 cm ). The aim of the research was to identify the highest height that can be achieved in the sample of volleyball players when performing the deep jump immediately after an initial jump from the height of (15 cm and 30 cm) and determine the highest value of the electrical activity of the outer membrane of front thigh muscle when performing this jump in addition to identifying the statistical differences between players achieving the highest height when performing the deep jump after the initial jump from (15 cm and 30 cm) and the significant relationships between the achieved height and the initial height of initial jump ( 15cm and 30 cm) for volleyball players. The research determined the highest height achieved by the player after landing on the ground from a height of (15 cm and 30 cm) and the maximum value of (EMG), the statistical differences between, and the relationship between the maximum flexion of the knee joint and the highest elevation after the initial jump from (15 cm and 30 cm) the researcher recommended conducting similar researches in the same field for a number of other heights. (Published abstract)