Development and Evaluation of a Novel Ergonomic Ambient Display for Rectifying Poor Sitting Postural Behaviors

Abstract

Complete and accurate self-awareness of personal habitual behaviors can be a challenging task for modern day people. It is especially true when it comes to old habits, such as those of sitting postures. Awkward sitting postures, which are known to be a risk factor of work-related musculoskeletal disorders, are by and large habitual. Due to their habitual nature, seated workers find it difficult to detect the occurrences of awkward sitting postures and correct them in a timely fashion. A system which enhances a seated workers awareness of working posture with little disturbance to computer task would greatly help reduce physical stresses associated with seated work tasks. Several studies have developed systems that monitor a workers sitting behavior in real time and provide feedback to users when necessary

yet, few empirical studies were conducted to compare different display types and there is no consensus on which type of feedback display is the most suitable for daily use. As an effort towards developing an effective system for enabling awareness of sitting posture in an unobtrusive manner, this study developed a novel ergonomic ambient display based on the multiple resource model. The display used ambient light in the peripheral visual area to convey feedback information to computer users. An empirical study was conducted to evaluate the ambient display in comparison with a typical pop-up display. The evaluation criteria were the effectiveness in rectifying poor sitting posture, the level of interference in the primary computer task, the detectability of feedback alarm during primary task, and user acceptance. A posture feedback system based on a sensor-chair was developed and the same feedback algorithm was implemented in each display. Both displays were found to cause changes in the occurrence of poor sitting position. The percentage of time of poor postures was similar in the ambient display and the pop-up display conditions. Also, the ambient display interfered computer task less than the pop-up display with lower mental workload. The results of subjective ratings showed that the ambient display was more visible during the computer tasks and was expected to contribute to posture correction more than the pop-up display. The results of this study seems to support the fourth dimension of the multiple resource model. Further studies for a long-term study of the ambient display and the development of adaptive ambient display are suggested. The findings from this study will be of great help to the engineers and designers, who are interested in using ambient display to develop an effective digital device to evoke changes in human behavior.