自然步態轉換在運動學及生理學上之分析

Abstract

自然步態轉換(PTS)和最佳化轉換速度(EOTS)在走跟跑上的特徵一直是生物力學及生理學學者探討的課題。本研究致在探討人類在在三種不同自然轉換速度底下之走跑形態，肌肉神經及生理學系統參數在趨勢上的改變。十二位男性受試者自願參與本實驗。本研究使用之儀噐分別有Vicon®動作擷取系統、Biopac®肌電擷取系統及Cosmed®心肺功能測量系統。結果顯示大腿及小腿肌電訊號在iEMG ECC/CON ratio上可顯示生理代謝率在三個自然轉換速度上的改變。小腿肌肉在走路速度低於100%PTS時效率比較低。而當走路速度增加到100%PTS跟125%PTS之間時，大腿肌肉也隨之變得效率較低。筆者認為這結果可闡明肌肉彈性位能在兩種步態及不同的自然轉換速度的關係。當增加走路速度時會減少人類使用肌肉彈性位能的能力，反之跑步卻可以比較使用到肌肉彈性位能。本研究結果結合生物力學及生理學並為自然步態轉換提供了一個合理的解釋。

Preferred Transition Speed (PTS) and Energetically Optimal Transition Speed (EOTS) for walk and run were two of the phenomenon which has been explored by exercise physiologist and biomechanist. The present study attempted to determine trend of the neuromuscular and metabolic change among three selected percent PTS and two locomotions (walk and run). Twelve male subjects were invited to be the participants in this study. A Vicon® motion capture system, Biopac® Electromyography and Cosmed® Indirect Calorimeter were used to determine the kinematic, neuromuscular and metabolic expenditure, respectively. The results showed that Thigh/Shank iEMG ECC/CON ratio may illustrate the metabolic change among different levels of PTS. A significant inefficiency shank muscle activation was initially occurred under 100%PTS, furthermore thigh muscle became inefficiency under 125%PTS. By reviewing the literatures and interpolate current study, we found that this result may illustrate the use of “muscle elastic capacity” among the type of locomotion and different PTS. During walking, the increase of locomotion speed might lead to decrease the ability for using the muscle elastic energy, whereas it is inverse for running. The value of this study was to provide a possible way to clarify the unexplored area between physiological and neuromuscular system on PTS.