本研究主要目的在比較受試者在以不同之速度跑步下，左右腳著地期地面反作用力第一峰值、第二峰值、負荷率、退化率、地面反作用力之差異。 本研究以輔仁大學碩職班六人為受試對象，使用Gaitway系統，以不同之速度在跑步機上跑步，取樣速度為走路4、4.5、5km/hr，取樣頻率為每秒100HZ及慢跑6-17km/hr，一次增加一公里，取樣頻率為每秒300HZ，每一階段收集10秒鐘之跑步週期資料進行分析，再使用Gaitway軟體進行動力學資料處理，所得結果如下： 一、 速度超過7km/hr時第二峰值消失，可能是當跑步速度達到一定程度後，使用足尖推撐的情形將大幅減少。 二、 左右腳的地面反作用力與跑步速度呈現正相關，速度越快雙腳的地面垂直反 作用力越大。 三、左右腳負荷率並無明顯的差異。 四、退化率與跑者的速度成正比。 五、速度越快負荷率越大。 根據以上發現，跑者在第一峰值、第二峰值、地面反作用力、負荷率及退化率皆與跑者速度有關。

The purpose of this study want to find the different of first peak force, the second peak force, loading rate, decay rate, counterforce of ground reaction forces when testees in different running speeds. The testees of this study are six on-the-job graduate students of Fu Jen Catholic University. “Gaitway” system will be used in this study with different speeds. Sampling speed of walk are 4.5, 5 and 6 km/hr in 100Hz sampling frequency per second. Sampling speed of jog are 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and 17 km/hr in 300 Hz per second. Collect data for ten seconds in exercise lifecycle for analysis in every step and use the software of “Gaitway” to do the data processing. The following conclusions of this study have been reached: The second peak force will be disappeared while speed over 7 km/hr. Maybe it’s because when the running speed reached a certain conditions, the situation of running in tiptoes decreases dramatically. 1. Legs ground reaction forces have positive correlations with running speed. 2. The vertical ground reaction forces increase in faster speed. 3. No obvious difference of loading rate between left and right leg. 4. Decay rate is directly proportional to running speed. 5. loading rate will increase by running speed. According to the findings above, the first peak force, the second peak force, ground reaction force, loading rate and decay rate all have relationship with runner’s speed.