由地面反作用力評估鞋底避震能力

邱宏達

指導教授 ： 林德嘉 ； 相子元

國立臺灣師範大學/運動與休閒學院/體育學系/博士(1999年)

摘要

摘 要
過去已有許多的研究以材料及人體測試的方法，探討運動鞋的避震能力，但兩種測試的結果並不一致。本研究試圖由實驗及模式分析的方法，由撞擊期地面反作用力曲線，瞭解兩種測試之間的異同，並藉此改變材料測試的方法，使其更接近實際人體測試的情況。
本研究針對市售的Nike慢跑鞋進行材料與人體測試。材料測試結果顯示，撞擊的能量增加，垂直地面反作用力的最大負荷率及傳導至撞擊器的慣性力峰值會隨著增加，且在能量大於5焦耳時，鞋底的避震效果明顯降低。人體測試所測得著地初期垂直地面反作用力曲線，與材料測試所得的曲線相近，但人體測試的撞擊力峰值較高，因此材料測試可評估人體實際跑步時所受地面反作用力的最大負荷率。模式分析結果可說明人體測試中測得較高的撞擊力峰值，應與撞擊過程中有效質量的增加有關。赤腳跑時，四位受試者著地瞬間膝關節較彎曲、角速度較大，小腿縱軸較垂直地面，足底與地面夾角較小，且足跟水平速度也較小，此顯示赤腳時受試者為避免足底承受過大的壓力及撞擊負荷，因而改變著地的策略。
若以最大負荷率來評估鞋底避震的效果，則由兩種測試的結果比較可計算出實際跑步時的撞擊能量，本研究四位受試者的跑步速度控制在3 m/sec，推算出撞擊能量約在3∼7焦耳。因此，若能改變材料測試中撞擊器重量與撞擊高度的範圍，使其與實際跑步的撞擊能量相近，如此即可快速得知慢跑鞋在不同撞擊能量下避震特性的改變，並可評估實際慢跑所測得最大負荷率的範圍。本研究的方法與結果，可提供作為國內對慢跑鞋避震功能材料測試標準訂定之依據。

關鍵詞：慢跑鞋、避震、地面反作用力、材料測試、模式分析

並列摘要

ABSTRACT
Two methods have been carried out to evaluate the cushioned properties of running shoes: material and subject test. However, there are conflicts between the two tests. The purpose of this study is to investigate the differences and similarities between the two tests using ground reaction force (GRF), then try to change the approach of the material test to fit the actual running situation.
A commercial running shoe was tested in this study. The result of the material test showed that increasing impact energy would get the larger maximum loading rate and inertial peak force and the cushioned property of the shoe would be reduced significantly when the impact energy was over 5 joule. The curves of vertical GRF during the initial impact phase in subject test were similar to the results of material test. Thus, the material test could evaluate the maximum loading rate of the vertical GRF as actual running. Modeling analysis, used in this study, indicated that because the effective mass added into the impact phase there was a larger impact peak force occurring in the subject test. In barefoot running, the larger knee flexion and angular velocity, more vertical position of the shank, flatter foot placement and smaller horizontal heel velocity in the landing instant were the adaptation strategies of the subjects to reduce the plantar pressure under the heel and the impact loading.
With the comparison of the material and subject test, the impact energy during actual running could be evaluated correctly. The impact energy of the four subjects running with 3m/sec in this study were 3∼7 joule. Therefore, if change the impact weight and the impact height of the striker into adequate region that similar to the actual running situation, the maximum loading rate of the vertical GRF during running could be evaluated faster with material test. This study was able to establish the standard for material test to evaluate the cushioned properties of the running shoes.

Key words: Running Shoe, Cushion, Ground Reaction Force, Material Test, Modeling Analysis

參考文獻

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