The researchers aimed at: identifying indicators of the electrical activity of the working muscles (the average electrical activity of the working muscles, the maximum muscle contraction, the total value of the electrical activity of the working muscles, and the contribution of the electrical activity of the working muscles to the working muscles) of the sample under study, as well as the percentages of the electrical activity contribution of the working muscles during the performance of the sample under consideration. The researchers used the descriptive approach, and the sample included a player who threw an international spear within the Egyptian national team and holds many international championships and is ranked second in the world. The most important results: The biceps muscle, the anterior deltoid muscle, and the subfork muscle are the highest rates of contribution to performance for analyzing the electrical activity of the muscles in the three attempts under consideration, which indicates the importance of these muscles during the javelin. The lower limb muscles (femoral straight muscle (right) and lateral lateral muscle (right) and femoral biceps muscle (right) have the highest rates of contribution to performance according to the electrical activity analysis of the muscles in the first, second and best attempts at the digital level being considered. Left) and the straight muscle Femoral (left) and anterior bronchial muscle (left) and lateral lateral muscle (left) are the lowest contribution ratios in performance according to the analysis of electrical activity of the muscles in the three attempts under consideration. The researcher recommended: guiding the results that were reached as values for the muscular activities and their contribution ratios. Directing and caring for them during the training leads to raising the level of performance of the javelin players, using the electrical muscle planning (EMG) to find out the condition of the javelin throwing muscles and developing them through the fine details that It is difficult to observe with the naked eye, the use of the results of the electromyography (EMG) in preparing training programs