固定負荷下橢圓機運動之下肢肌群疲勞分析

Abstract

橢圓機為一項心肺適能的運動訓練器材，近年來逐漸受到一般家庭以及健身俱樂部的廣泛使用。 對於橢圓機的運動方式，及其所產生的不同強度對下肢肌肉造成之疲勞，有進一步的整合與探討的必要。本實驗收集下肢肌肉的肌電訊號，再以商用軟體分析可能發生疲勞的時間點。因此，本研究利用分析疲勞的系統，以固定阻力的方式分析使用橢圓機造成下肢肌肉疲勞等部分，進行相關文獻的整理，並規劃實驗方法及分析所得結果。本研究以十位初次使用橢圓機的年輕人為受試對象，實驗操作方式以自然踩踏為主，將肌電訊號進行傅立葉轉換，再以中位數頻率下降至最大值的80%為輕度疲勞來判定，結果判顯示有60%的受試者前大腿的股直肌最先出現疲勞之情況。 因此，橢圓機踩踏時，較易使用到前大腿的肌肉，並造成疲勞。大部分的疲勞是由於下肢肌肉過度使用的關係。藉由了解橢圓機的生物力學，能夠改善及降低運動疲勞傷害。結果顯示此系統能分析可能產生疲勞之時間點，此分析結果期能協助橢圓機使用者於運動中避免造成傷害，同時可增加橢圓機訓練的效率。

The elliptical machine is one of the most popular sports equipment for cardiorespiratory fitness training. In recent years, it is widely used in the family and the gymnasium. Therefore, it is necessary for further discussion about the movements of the elliptical machine, and various levels of the lower-limb muscular fatigue using the elliptical machine in various strengths. The research collected the electromyography (EMG) signal of lower limb muscles, and used the commercially available software to analyze the possible timing that the fatigue appeared. The research applied this system to analyze the lower-limb muscular fatigue when using the elliptical machine with a constant resistance. It compiled the relevant literature, developed the experimental methods and analyzed the results. The subjects of this research arranged ten young people who used elliptical machines for the first time. They carried the EMG and pedaled in a nature way. Then, Fourier transform was applied for all collected data, and the median frequency was calculated from 80% of the maximum value of the mild fatigue. The result showed that 60% of subject's rectus muscle had been fatigued first. As a result, when using the elliptical machine, it was much easier to use the muscles of the front thigh and get tired. Most of the fatigue occurred from overusing the lower limb muscle. By understanding the biomechanics of the elliptical machine, it could improve or reduce the fatigue and injuries during exercise. The system can analyze the fatigue timing as well. The fatigue analysis results could help elliptical machine users to avoid injuries, and increasing the efficiency of elliptical training.