硏究對象은 17~20歲의 男子로서 射擊選手 8名과 非選手 12名을 選定하였으며, 筋電圖測定은 表面電極法으로 하여 射擊姿勢인 擧銃, 照準, 및 擊發時에 上肢筋의 筋電圖를 描記하여 振幅, 頻度 및 集積筋電圖를 測定하였다. 이와같이 射擊動作時에 上肢筋의 筋電圖 變化樣相을 究明함으로써 射擊指導에 있어서 參考資料를 얻고자 하여 描記한 筋電圖의 變化를 要約하면 다음과 같다. 1) 兩群의 比較에서 三角筋과 大圓筋은 選手群이 높았으며, 이중 三角筋의 擊發과 大圓筋의 擧銃, 및 擊發은 非選手群에 比해 有意하게 높았다. 이에 反해 前腕屈筋 및 前腕伸筋은 選手群이 오히려 낮았고 二頭筋 僧帽筋 및 三角筋은 兩群사이에 別 差異가 없었다. 2) 擧銃에 對한 比較에서 照準, 擊發順으로 높았으며, 이 中 非選手群에서는 大圓筋의 照準 및 擊發과 前腕屈筋 및 前腕伸筋의 擊發이 擧銃에 比해 有意하게 높았고 選手群에서는 前腕屈筋의 擊發이 有意하게 높았다. 3) 二頭筋에 對한 比較에서 三角筋과 僧帽筋이 가장 높은 振幅으로 有意하게 높았으며, 다음이 大圓筋 順이며, 그외 上肢筋은 二頭筋과 別 差異가 없었다. 頻度에서 1) 兩群問의 比較에서 三角筋은 選手群이 높았고, 前腕屈筋, 前腕伸筋은 오히려 낮았으며, 二頭筋, 僧帽筋, 大圓筋, 三頭筋은 別 差異가 없었다. 2) 擧銃에 對한 比較에서 대부분 照準, 擊發의 順으로 낮았으며, 選手群에서는 大圓筋의 照準이 有意하게 낮았으며, 非選手群에서는 僧帽筋의 擊發이 有意하게 낮았다. 3) 二頭筋에 對안 比較에서 選手群의 三角筋이 擧銃, 照準, 擊發時 有意하게 높았으며 나머지는 別 差異가 없었다. 集積筋電圖에서 1) 兩群 比較에서 上肢筋 모두 選手群이 非選手群에 比해 낮았으며, 이 중 僧帽筋과 前腕伸筋은 모두 射擊姿勢에서 有意하게 낮았으며, 大圓筋은 擧銃時에 前腕屈筋은 擊發時에 有意하게 낮았다. 2) 擧銃에 對한 比較에서 照準, 擊發順으로 낮았으며, 이중 非選手群에서는 三角筋의 擊發時가 擧銃時에 比해 有意하게 낮았고 選手群에서는 僧帽筋의 照準과 三角筋 및 前腕屈筋의 擊發이 有意하게 낮았다. 3) 二頭筋에 對한 比較에서 三角筋과 僧帽筋이 가장 높은 集積筋電圖로 有意하게 높았으며, 그 외 上肢筋은 二頭筋과 別 差異가 없었다. 以上의 結果를 綜合해 보면 射擊動作時 筋電圖의 振幅은 擧銃, 照準 및 擊發 順으로 增加한데 比해, 頻度 및 集積筋電圖는 오히려 減少했으며, 이 中 特히 選手群의 前腕屈筋의 振幅이 擊發時에 有意하게 增加한데 反해, 非選手群에서는 擊發時 弛緩되어야 할 前腕伸筋의 振幅이 有意하게 增加한 點과 選手群의 三角筋의 振幅과 頻度가 非選手群에 比해 높고, 上肢筋을 固定하는 大圓筋의 振幅이 選手群에서 또한 높게 나타났고 特히 選手群의 集積筋電圖는 非選手群에 比해 모두 낮은 點, 그리고 射擊動作時에 上肢筋中 三角筋과 僧帽筋이 가장 높은 振幅, 頻度 및 集積筋電圖를 나타낸 點 等은 意義있는 事實로 注目되는 바이다.

Eight male shooting athletes and twelve non-athletes were selected for the subject of this study. Electromyogram (EMG) was recorded with surface electrodes on the upper limb muscles during “high”, “aim”, and “fire” motions. Amplitude, frequency and integrated EMG, were maesured from the record. Effort were directed to elucidate the changes in EMG during acts of shooing. The results obtained are summarized as follows. Amplitude: 1) In comparison between two groups, EMG amplitudes on the deltoid and teres major were higher in athletes than in non-athletes. The difference was significant on the deltoid during “fire” and on the teres major during “high” and “fire”. The amplitudes on the forearm flexors and extensors, on the other hand, were lower in athletes than in non-athletes. There was no difference between two groups on the biceps, triceps, and trapezius. 2) In comparison among the motions, the amplitude during “fire” was highest, followed by those durng “aim” and “high” in the order named. In non-althletes, the amplitude during “aim” and “fire” on the teres major and that during “fire” on the forearm flexors and extensors were significantly higher compared with those during “high” on the respective muscles. In athletes, that during “fire” on the forearm flexors was significantly higher than that during “high”. 3) Compared with the amplitude on the biceps, amplitudes on the deltoid and on the trapezius were significantly higher, followed by that on the teres major. Frequency: 1) In comparison between two groups, the EMG frequency on the deltoid was higher and those on the forearm flexors and extensors were lower in athletes than in non-athletes. 2) In comparison among the motions, the frequency during “fire” was lowest, followed by those during “aim” and “high” in the order named. The frequency during “fire” on the trapezius in non-athletes and that during “aim” on the teres major in athletes were significantly lower than those during “high” on the respective muscles. 3) Compared with the frequency on the biceps, that on the deltoid during the 3 motions in athletes were significantly higher. Integrated EMG: 1) In Comparison between two groups, the integrate EMG on all the upper limb muscles was lower in athletes than in non-athletes. The difference was significant on the trapezius and forearm extensors during the 3 motions, on the teres major during “high”, and on the forearm flexors during “fire”. 2) In comparison among the motions, the integrated EMG during “fire” was lowest, followed by those during “aim” and “high” in the order named. That during “fire” on the deltoid in non-athletes and those during “aim” on the trapezius and during “fire” on the deltoid and forearm flexors in athletes were significatly lower than those during “high” on the respective muscles. 3) Compared with the integrated EMG on the biceps, those on the deltoid and on the trapezius were significantly higher. In conclusion, the EMG amplitude was increased in the order of “high”, “aim” and “fire”, but th frequency and integrated EMG was decreased in the same order. Attention should be given to the facts that the amplitude during “fire” on the forearm flexors was significantly increased inathletes while that on the forearm extensors was increased in non-athletes, that the amplitude and frequency on the deltoid was higher in athletes, that the amplitude on the teres major which fixes the upper limb muscles was higher in athletes, that the integrated EMG on all the muscles was lower in athletes, and that the amplitude, frequency, and the integrated EMG on the deltoid and on the trapezius were highest among the upper limb muscles.