不同坡度與速度下走跑對下肢肌肉活化的影響

Effects of walking and running at different slopes and speeds on muscle activation of lower extremity

目的：快走、健走與慢跑是非常容易執行且非常多人從事的運動，當跑步速度降低時常會介於走跑的轉換速度之間，了解轉換速度區間下走路與跑步對下肢肌肉的影響，將有助於提供健身運動的建議。健走或慢跑時常於戶外進行且有坡度變化，因此不同坡度的影響也有其了解的必要。目的：本研究以不同坡度 (10% 下坡、平地和10% 上坡) 與不同速度 (75%、100%、125%的轉換速度) 下，比較不同坡度下走路與跑步差異，進而探討人體肌肉活化的變化，期能提供使用跑步機訓練時的參考依據。方法：本研究招募 12位有規律運動的男性實驗參與者，實驗過程分為兩階段：第一階段為轉換速度的訂定；第二階段收集在三種不同坡度與三種不同速度下，走路與跑步慣用腳的下肢肌肉 (股直肌、股二頭肌、脛前肌與腓腸肌) 活動情形。統計採用重複量數三因子變異數分析，顯著水準定為 α =.05。 結果：所有受試者在不同坡度下其轉換速度之平均值，分別為7.24 km×h-1 (平地)、7.19 km×h-1 (下坡)、6.63 km×h-1 (上坡)。支撐期時，在上坡且高速的情境下，走路時的下肢肌群的平均肌電皆大於跑步時。擺盪期時，在平地、下坡及上坡且高速的情境下，走路時的下肢肌群的平均肌電在皆大於跑步時；在不同坡度及速度的情境下，跑步時的下肢肌群的平均肌電的影響較不明顯。不同坡度情境下，上坡走路時的肌肉活動量大於平地與下坡。結論：不同的坡度與速度變化，會對走路的下肢肌肉活動產生明顯影響，對於跑步則較不明顯。當行進速度大於轉換速度時，走路的下肢肌肉平均肌電活動量大於跑步。本研究建議，可以快走的方式取代慢跑，並加入坡度上的變化，增加訓練時的強度與身體活動量。

 

Walking and running could be the most popular exercise. Activation level of the Lower extremity muscles at time of running or walking relates to at least two essential factors: preferred transition speed and inclination angle of the running surface. Understanding the relationship among those factors may help physical trainers provide appropriate fitness advice to the participants. Purpose: This study compared lower extremities’ electromyographic (EMG) activities with two varied conditions: running speed (75%, 100%, 125% of the preferred transition speed, PTS) and varied inclinational slope of the running ground (10% downhill, level, 10% uphill). Methods: Twelve male subjects were invited to voluntarily participate in this study. The experiment is comprised of two parts. Part one was to determine the PTS at the given slopes, and part two was to collect EMG activities at conditions of varied running speed and varied ground slopes. Four leg muscles: rectus femoris, bicep femoris, tibialis anterior, and gastrocnemius were chosen as the studied muscles in this study. Three-way ANOVA was used to examine groups’ difference, and significant level was set at level of p value less than 0.05. Results: The average of the transition speeds of all subjects among level, downhill and uphill slope were 7.24, 7.19 and 6.63 km×h-1 , accordingly. The results showed that, in stance phase, walking was found to activate higher EMG activities for the lower extremity than that of running at uphill and high-speed condition. However, in swing phase, walking was found to generate more averaged EMG activities for the lower extremity than that of high-speed running among level, downhill and uphill condition. Conclusion: Running speed and ground-surface slope are two crucial factors determining EMG behaviors of the lower extremity muscles. Walking with speed higher than the preferred transition speed would facilitate higher EMG activation and produce larger averaged EMG activity than that of running at varied ground’ slope and speed.