The researcher aimed: to identify the quantitative values of electrical activity of working muscles (indicators of electrical activity of working muscles - percentages of indicators of electrical activity of working muscles - correlational relationships between indicators of electrical activity of working muscles and the digital level in javelin throwing during the disposal phase in javelin throwing for the sample under study. The researcher used the descriptive approach using the (EMG) device for the electrical activity of the muscles, The research sample included: the player Ihab Abdel Rahman, the javelin thrower (Egyptian national team players and the international player). Among the most important results: the muscles of the upper limb of the body achieved a percentage of 54.5% of the total values of the average electrical activity of the muscles, and the muscles of the upper limb of the body achieved a percentage of 53% of the total values of the contribution of electrical activity of the muscles, and the muscles of the upper limb of the body also achieved A percentage of 51% of the total values of the maximum muscle contraction, the muscles of the lower limb of the body achieved the right leg (the pushing leg) a percentage of 31% of the total values of the average electrical activity of the muscles, and the muscles of the lower limb of the body achieved the right leg (the pushing leg) A percentage amounted to 31.5 % of the total values of the electrical activity contribution to the muscles. Also, the muscles of the lower limb of the body, the right leg (the pushing leg), achieved a percentage of 28% of the total values of the maximum muscle contraction. The muscles of the lower limb of the body, the left leg (the pivot leg), achieved a percentage A percentage amounted to 14.5% of the total values of the average electrical activity of the muscles, and the lower limb of the body, the left leg (the pivot leg), achieved a percentage of 15.5 % of the total values of the electrical activity of the muscles, and the lower limb of the body also achieved the left leg a percentage of 21% of the total values of maximum muscle contraction. The researcher recommended: Using the electrical activity of the muscles (EMG) to find out the condition of the muscles of the javelin throwers and develop them through accurate details and use them in building and developing training programs in all field and track competitions and races.