本研究主要是藉由分析國小學童過肩投擲動作經六周訓練前後其上肢肌肉肌群肌電活動之差異來探討肌肉在投擲過程所扮演之角色。實驗參與者為國小高年級學生9名(平均年齡11.15±0.29歲，身高143.22±6.03公分，體重46.12±10.88公斤)，參與六周過肩投擲動作練習。肌電訊號以一部Noraxon無線肌電系統收集練習前後上肢肌群(肱二頭肌、肱三頭肌、伸腕肌及屈腕肌)之肌電資料，再進行帶通濾波(bandpass，30~500Hz)、翻正(Abs)、低通濾波(low-pass filtering，10Hz)處理後以最大肌肉收縮標準化(MVC%)獲得肌肉活化程度。實驗結果經配對t檢定分析後，其檢驗的顯著水平定為.05，本研究結果經分析與討論後，獲得下列結論：訓練前後在肱二頭肌、肱三頭肌與屈腕肌之肌電值達顯著差異(p < .05)，而伸腕肌之肌電值並無顯著之差異；另外肱二頭肌、肱三頭肌與屈腕肌之肌電值在訓練前後均有減少的情形，而伸腕肌之肌電值則有增加的情形。

This study by the analysis of elementary school students over the shoulder throwing motion by the differences in upper limb muscles before and after six weeks training muscle EMG activity to explore the role played by the muscles in the throwing process.Study participants for the fifth and sixth grade 9 students (average age 11.15 ± 0.29 years old, height 143.22 ± 6.03 cm, 46.12 ± 10.88 kg body weight) to participate in the six weeks the shoulder throwing motion exercises. The EMG wireless EMG system collected a Noraxon upper limb muscles (biceps, triceps, wrist extensor muscle and flexor carpi muscle) EMG data before and after exercise, then band-pass filter (bandpass, 30 500Hz), the standardization of righting (Abs), low-pass filter (low-pass filtering, 10Hz) after treatment with the greatest muscle contraction (MVC%) of muscle activation level. Experimental results analyzed by the paired t test, its test level of significance set at .05, the results of this study, after analysis and discussion, the following conclusions: before and after training, the muscles in the biceps, triceps and flexor carpi power value of significant differences (p <.05), no significant differences; wrist extensor muscle EMG value addition, the EMG of the biceps, triceps and flexor carpi value before and after training, there was a decline the case of the wrist extensor muscle EMG increased.