不同著地型態下赤足與穿鞋跑走之生物力學分析

Abstract

目的：探討後足與前足二種不同著地型態之跑步與走路，對人體下肢生物力學特性之影響，並比較二種著地型態之間有無穿鞋的差異。方法：招募12位男性受試者，其著地動作型態皆為習慣足跟先著地，採平衡次序法進行不同著地型態動作穿鞋或赤足的跑步與走路動作，透過動作分析系統、表面肌電儀與裝有負重元之跑步機進行資料收集。統計使用二因子重複量數進行分析，顯著水準設為α =.05。結果：在不同著地型態的跑與走，前足著地產生較小的負荷率，而且產生較大的膝關節著地角度與著地至重心距離。預先收縮期與著地期的肌肉活化表現方面，前足著地跑步的腓腸肌活化程度大於後足著地，然而脛前肌則為後足著地大於前足著地。在赤足的情況下，跑步的步頻、膝關節著地角度與踝關節的活動度均增加。但是，赤腳後足著地產生的負荷率較大，造成下肢勁度增加。結論：前足著地方式可降低著地時的負荷率，主要是改變著地型態後增加膝與踝關節的活動，然而下肢肌肉使用情形又與後足著地型態相反，因此可訓練到不同肌群。由於赤足的後足著地方式會產生更大的負荷率，因此赤足的運動方式必須適當調整著地型態。

Purpose: The purpose of this study was to investigate the lower limb biomechanical characteristic of different foot strike patterns with running and walking. Also, we want to compare the difference of two patterns between barefoot and wearing shoes. Methods: There were twelve male subjects recruited in this study. All subjects were rearfoot strike runner. Different foot strike patterns between barefoot and wearing shoes with running and walking by the counter-balance method. For data collection, we used vicon 3D motion system, surface EMG and load cells. Two factor repeated design (two-way ANOVA) was used to analyze, significant level was set at α=.05. Results: The results showed that forefoot strike pattern have lower loading rate, and also, forefoot strike have more knee flexion angle when foot contact on the ground and greater center of gravity to foot strike distance. The EMG data of muscle pre-activation phase and stance phase gastrocnemius showed higher activation in forefoot strike than in rearfoot strike. However, tibialis anterior showed higher activation in rearfoot strike. In barefoot running condition, the results showed that running barefoot have higher stride frequency, knee flexion angle at foot strike and range of motion of ankle joint than in running with shoes. But, rearfoot strike with barefoot have higher loading rate and increased leg stiffness. Conclusion: This study demonstrated that the loading rate was lower in forefoot strike than in rearfoot strike, because forefoot strike has higher knee flexion angle and higher ankle plantarflexion. The lower limb muscle activation is different from the rearfoot strike. And then, it may contribute to obtain other muscles training. Comparing with shod and barefoot running showed higher impact in rearfoot strike with barefoot condition. Therefore, the suggestion for barefoot running is to adjust the foot strike pattern appropriately.