Workstation improvement to reduce muscular fatigue of workers in air conditioner factory

Abstract

The objectives of this study were to design a workstation for reducing muscular fatigue in workers hanging materials on an overhead conveyor at an air conditioner factory by using a model to improve workstation height. The existing workstation's work height of 176 centimeters was modified to 136.6+1.52 centimeters by using standing base 40 centimeters height and lifting equipment. This quasi-experimental study was carried out with 20 male workers. All subjects had no history of serious illness or musculoskeletal injuries. The mean age of the study subjects was 27.55+1.36 years. Mean weight and height were 60.80+1.92 kilograms and 165.01+1.59 centimeters respectively. The duration of work as workers for hanging materials on overhead conveyors was 4.67+0.46 years. The subjects were both objectively and subjectively assessed for fatigue while working on the existing workstation and also on the improved workstation. The percentage of maximum voluntary contraction (MVC) was measured by electromyography every 30 minutes, and fatigue feeling was assessed by a questionnaire at 0, 3, 4 and 6 working-hours. The results of this study demonstrated that while the workers worked on the improved workstation, the fatigue feeling of the general body, deltoideus muscle and erector spinae muscle was significantly less than that while working on the existing workstation (α = 0.05). The percentage of MVC of deltoideus muscle and erector spinae muscle during working on the improved workstation was significantly less than that while working on the existing workstation (α = 0.05). Workplace temperatures during the experiment remained constant. Finally, on the improved workstation, the duration of each item was significantly less than that while working on the existing workstation (α = 0.05). The experimentation indicated that anthropometrics data of the workers would be very useful as design criteria for workstation improvement in order to reduce muscular fatigue. Therefore, this study concluded that the improved work;"การวิจัยครั้งนี้มีวัตถุประสงค์ในการออกแบบปรับสถานีทำงานเพื่อลดความเมื่อยล้ากล้ามเนื้อไหล่และ กล้ามเนื้อหลังของพนักงานแขวนชิ้นงานบนราวลำเลียงในอุตสาหกรรมผลิตและประกอบเครื่องปรับอากาศ โดยนำแบบจำลองมาประยุกต์ใช้ในการปรับสถานีทำงานเดิม ที่มีความสูงของจุดแขวน 176 ซม. เป็นสถานีทำงานใหม่ที่มีความสูงของจุดแข"