Is standing office ergonomic? Effects of working posture type on body discomfort and physical demand

Abstract

It seems that sedentary working with sitting posture for a long time is natural for office workers. It is not a surprising news that the participants who answered Ergotron’s survey complained sitting posture. More than 70% of participants replied that they have to maintain sitting posture even if they do not want. It can be interpreted as standing is not a perfect solution for working environment. Many different alternatives were suggested instead of sitting office. Among them, standing office seems reasonable but still it has inevitable problems to use standing posture only. Stool is needed to explore that it could diminish the problem that standing posture have but the previous research did not examine much. The main goal of this study was to find out standing office is really ergonomic or not for office workers and could it be make sense to use stool as a substitute for office chair. In this study, meaning of ergonomics were focused on the physical comfort. Twenty-eight healthy young adults were recruited for the experiment who use desktop or laptop frequently for studying or working. Task was performing documentation works with standing posture, sitting on stool and sitting on chair for 20-minutes duration. Prior to each task and after performing the task, subjective rating score was evaluated and circumference of each leg were measured. During the task, surface electromyography signal, movement of body segment and foot force were measured. Offered furniture like table, chair and stool were height adjustable and prior to task, participants could adjust all furniture segment and desktop monitor. Study result proved that standing office is more ergonomic than sitting office. Participants kept body posture more neutral, following office ergonomics guidelines while standing. Viewing angle while sitting on stool and chair was lower than the suggestions in the guideline. Viewing distance was kept within a certain range while standing but for sitting on stool and chair showed increased trend compared to reference posture. Neck angle was kept straight only for standing posture. However, standing posture was not good for lower extremities to avoid muscle fatigue. It showed significantly higher than other conditions for gastrocnemius muscle. Stool seemed to have a possibility of being an alternative of office chair. It showed better performance on muscle activity and posture than chair condition. Chair condition caused higher muscle activation in upper trapezius area than other conditions. Stool condition caused almost same performance to chair condition except upper trapezius area. That is, it might be better to use stool for sitting posture than office chair. The result of this study suggests that combining standing posture and using stool might be the better solution than using only sitting on a chair for physical comfort of office workers.