不同步態在足跟著地時下肢運動學與撞擊能量之關係

Correlations between the kinematics of lower extremities and impact energy at heel strike for walking%2C jogging and running

前言：本研究在預估不同步態下，人體足部與地面撞擊能量的大小，並探討下肢運動學與撞擊能量的相關性。方法：以不同的撞擊能量撞擊受測鞋，計算撞擊能量與地面反作用力之最大負荷率的線性迴歸關係。另招募14名男性受試者，穿著與材料測試相同之慢跑鞋，進行快走、慢跑及快跑的動作，以visualeyez動作捕捉系統拍攝並計算下肢的運動學參數，經由比較材料與人體測試的地面反作用力，以預估撞擊能量大小。結果：快走、慢跑及快跑著地時的撞擊能量分別為0.81±0.45焦耳(0.45~1.85焦耳)、1.55±0.56焦耳(1.07~2.08焦耳)，2.97±1.39焦耳(2.06~4.00焦耳)。快跑著地瞬間的足跟速度最快，踝關節角度最大，膝關節角度最小，依序是慢跑及快走。撞擊能量與足跟速度(r=0.647，p<0.01)呈顯著的負相關。結論與建議：未來如欲以材料測試評估慢跑鞋在不同步態下的避震效應，所採用的撞擊能量應設定在0.45~4焦耳。人體在不同速度下的運動，為減少衝擊下肢會採取運動學上的調整，但著地時的撞擊能量仍會隨運動速度增加而增加。導致撞擊能量增加的原因，相較於有效質量，撞擊速度的影響似乎更為主要。

Purpose: The purpose of this study is to estimate the impact energy at the landing instant for walking， jogging and running with running shoe and to investigate the correlation between foot strike kinematic factors with impact energy. Methods: A portable impact tester was specifically designed to impact a running shoe (Nike air shox 318684-142) that was positioned on a force plate (AMTI BP400600) with 10 different impact energies (equally distributed from 0.61 to 6.08 joules). The linear regression equation between mean maximum loading rate and impact energy was calculated for this shoe. Fourteen male subjects wearing the same shoes of material test were asked to move across the force plate by walking， jogging and running. The heel velocity， ankle and knee angle at heel strike were measured by using 3D motion analysis system (VisualeyezTM， VZ4000). The impact energies were calculated with the comparison of the ground reaction forces of impact and subject testing. Results: The impact energy for walking， jogging， and running was 0.81±0.45 joule (0.45~1.85 joule)， 1.55±0.56 joule (1.07~2.08 joule) and 2.97±1.39 joule (2.06~4 joule)， respectively. The kinematic factors: heel velocity(r=0.647， p