從防滑與保護足部的觀點探討勞工鞋的設計與製造

The Design and Manufacture of Working Shoes from the Viewpoint of Prevention of Slipping and Protection of Foot and Ankle

勞工工作場所存在著眾多的滑倒媒介物，如積水、凹凸不平表面與油漬等，如何防止滑倒，對於保障勞工安全來說是一個非常重要的研究課題。本研究的主要目的是探討不同鞋底材料其防滑程度的差異，以提供勞工選擇安全鞋之參考，並且建立肢體於滑倒及平衡時之足踝部運動模型，希望藉以發展出有效的防滑理論，以減少勞工因滑倒所造成之傷害。本研究利用動態分析系統對二十位受測者，穿著五種不同鞋底材料之鞋子，進行正常界面與油界面的步行實驗。由動態分析系統所得之運動學資料及測力板所得的反作用力資料，配合所建立之足部運動力學模式，經電腦計算可得到水平力與垂直力之比值（FH/FV），踝關節之位置、角速度、角加速度之變化情形及肢體活動時所需最大力矩及能量消耗情形。實驗結果顯示，滑倒大約發生於腳跟著地之後0.05秒，滑倒發生時角速度及角加速度有極大的變化，並且踝關節力矩有增大的趨勢。由水平力與垂直力之比值來評估鞋底防滑性，結果發現硬化橡膠為一防滑性較佳之鞋底材料。同時從正常地面及油地面比較，油污染地面其摩擦係數很明顯變小，並且步行者有明顯打滑現象。從足部位置資料中，可發現若滑動距超過4公分，便有滑倒的危險。

Many mediums, for example, water, uneven floor and oil stains etc., resulting in fall can be found very often in the work environment. It is a very important issue for labor safety to prevent slips. The object of this research is to scrutinize and to study anti-slip assessments of the different outsole providing references to select the safe working shoes. A kinematic model of the foot-ankle is established to develop the valid anti-slip theory for reducing the slippery possibility. Twenty healthy people wearing five kinds of shoes with different outsole were tested on a normal floor and oil stained floor. The walking experiments were tested with motion analysis system and force plates. The kinematic data and reaction forces can be obtained from the walking experiments. The kinetic coefficient, i.e. the ratio of the horizontal and vertical forces, the position, angular velocity and angular acceleration of the ankle joint, the maximum moment and the consumed power rate can be calculated from the experimental data. In this research, it is found that the fall occurs at the time 0.05 seconds after heel strike. The angular velocity and acceleration are changed abnormally and the moment of the ankle joint is increased when fall occurs. The ratio of the horizontal and vertical forces is used to assess the effect of anti slipperiness. As a result of the anti-slip assessment, it is found that thermal plastic rubber (TPR) is a better outsole material. Comparing the normal floor with the oil stained floor, the oil stained floor leads to decrease in kinetic coefficient and increase in slippery possibility. From the position of the foot-ankle, it also can be found that a fall is more likely to occur if the sliding distance exceeds 4 cm.