Effect of Insufficient Environmental Brightness on Musculoskeletal System of Human Care Workers

研究亮度对工作作风的影响，以评估夜间经常在亮度不足下工作的护理人员的工作条件。为了记录被测物体在工作场所的相对位置，开发了控制电磁位置测量仪的软件。使用开发的系统，在1、10、40和150 lx的环境亮度下测量了行李搬运工作。10名受试者三次将8个盒子放在高低桌之间。在较暗的条件下，总工作时间增加。躯干倾斜度的标准差表示的姿势变化也增加了。对工作困难的主观抱怨在1lx显著。心理应激对亮度的影响较明显，而生理应激对亮度的影响不明显。在1、10、40和400lx的照度下，研究了环境亮度对人体护理模型工作的影响。四名受试者以工作人员和患者的身份参加了实验。工人用手动将病人从床上转移到轮椅上。它包括三个步骤：(1)使病人坐在床上的准备步骤，(2)转移步骤，(3)将病人的脚放在轮椅脚步上的安顿步骤。在较暗的条件下，工人在准备步骤时倾向于与床保持较远的距离。在安置点，工人们倾向于将脸靠近脚下的台阶。在转位步骤中，没有观察到位置和姿势的差异。在较暗的工作条件下，心理压力增加和脚步不确定性的主观诉求较为明显。

The effect of brightness on work style was studied to assess the working conditions of human care workers who often work under insufficient brightness in night.1. To record the relative position of a subject in a work place, a software that controls the electromagnetic position measuring apparatus was developed.2. Using the developed system, a baggage handling work was measured at the environmental brightness of 1, 10, 40 and 150 Lx. Ten subjects brought 8 boxes between the low and high tables for three times. Total work time was increased in the darker condition. The postural variation indicated by the standard deviation of the trunk inclination was also increased. The subjective complaint of difficulty for working was remarkable at 1 Lx. The effect of brightness was clear in mental stress, not in physical stress.3. The effect of environmental brightness on a model work of human care was studied at 1, 10, 40 and 400 Lx. Four subjects attended the experiment as both workers and patients. The worker transferred the patient from the bed to wheelchair by manual. It consists of three steps; (1) preparation step to make the patient to sit on the bed, (2) transfer step, and (3) settlement step to set the feet of the patient on the foot steps of wheelchair. The workers tended to keep more distance from the bed at the preparation step in the darker condition. At the settlement step, workers tended to keep their face near to the foot steps. No positional and postural differences were observed at the transfer step. The subjective complaint of increase in mental stress and uncertainty of footstep was clear when working darker condition.