Evaluation of Suitability of Retroreflective Material Locations by Motion Analysis of the Wearer of Safety Clothing

Since ISO 20471 regulations(2013) were enacted, high-visibility clothing made of fluorescent fabric and retro-reflective materials has been standardized to distinguish the wearers from the surrounding background in a dark place and to protect them. Accordingly, we made high-visibility safety clothing based on the international standards, and examined the positions of the retro-reflective materials on the attached sites to evaluate the suitability of the positions, by 3 types of safety clothing and the body regions when the wearers work or move. Two retro-reflective films of 5cm-horizontal lines were attached to the front/back of the upper-wear, and the lower-wear. Vertical lines were attached from the shoulder to the horizontal waistline. To analyze the motion in 3-dimension, we took pictured infrared-reflective markers on the retro-reflective film covered with yellow-tape on the front-side when 6 subjects wearing experimental garments performed 6 types of motions. According to the metronome tempo, the motions were performed for 30 seconds and repeated 6 motions ①∼⑥ by 3 experimental clothing. Among the 6 motions, significant differences in the appearance rate of the markers by body region during the motions were found in 5 types except for motion ③. Significant differences by the post-hoc test were shown in motions ④ and ⑥ as well. Therefore, for high-visibility safety clothing, it is necessary to anticipate the worker's motion and consider the attaching position of the retro-reflective material. It is considered desirable to attach the retro-reflective materials to several places where the clothing is hard to wrinkle.