本實驗目的以檢測肱二頭肌,分析動態漸增動作不同負荷下形成的肌電訊號,了解慢速阻力訓練動作不同負荷下,神經激活形式之變化。受試者為體育系學生及運動校隊選手21名,實驗以傳力器、關節角度計及肌電系統測量力量曲線、角位移及肌電訊號。資料經過處理後,以簡單迴歸進行統計分析,測試漸增動作不同負荷下形成的肌電振幅與肌電中位數頻率。結果發現肌電振幅隨負荷的提高而增加,即肌電振幅與負荷成正比;肌電中位數頻率則在不同負荷下保持一致,EMGMDF高低與負荷增減無關。顯示漸增動作阻抗不同負荷,其神經系統調控力量的機制與徵召之激活形式有關,而與激發頻率之激活形式無關。
To understand the neuromuscular activation patterns of the elbow flexor under different loads during weight training movement, we examined the electromyography (EMG) signal induced under different loads with ramp movement. Twenty-one young male physical education students or collegiate sport players voluntarily participated in this study. A force transducer, goniometer, and electromyographic system were used simultaneously with a data acquisition (DAQ) system to collect the signals for force, elbow angular displacement and EMG. The obtained data were analyzed by SPSS and simple regression was used to test the relationship between loads and EMG amplitude as well as the relationship between loads and EMG median frequency (MDF). The significance level was set at .05. The results revealed that the EMG amplitudes showed a linear positive correlation with the loads. On the other hand, the EMG MDF remained stable despite an increase in the loads. Therefore, the variation in EMG MDF was independent of the variation in the loads. These findings indicated that the linear relationship between activation pattern and load during ramp movement is attributable to fiber recruitment rather than firing frequency.