Abstract:
The objective of this thesis was to develop a device for postural change while sitting for the prevention of neck or low back pain in office workers. This thesis was divided into four stages: 1) to evaluate the effects of postural shifting frequency on perceived musculoskeletal discomfort during 1 hour of sitting in healthy office workers; 2) to evaluate the effects of the postural shift intervention on the 12-month incidence of the onset of neck and low back pain in high-risk office workers; 3) to investigate the efficacy of postural shift interventions on recovery duration and recurrence of neck and low back pain among high-risk office workers, and 4) to identify variables that moderate the effects of postural shifts interventions on the development of neck and low back pain in office workers. The finding of the first study showed that a postural shift frequency of 20-30 times/h significantly led to lower perceived discomfort in the neck, shoulder, upper back, and low back compared to a postural shift frequency of 10 times/h during 1 hour of sitting. These findings were used to develop a custom-designed device for postural change while sitting by the author and engineering team. The device consisted of three components: a seat pad, processor, and smartphone application. The device collected sitting behavior data and provided recommended postural shifting by gradually pumping air into various parts of the seat pad. The device had good to excellent validity and consistency. The results of the study two and three revealed that office workers who received the postural shift intervention significantly reduced the 12-month incidence rate, shortened recovery time, and reduced recurrence of neck and low back pain. Finally, the finding of the fourth study showed that workers who worked more hours/day and who endorsed higher levels of psychological work demand gained more benefits from the postural shift intervention regarding the prevention of neck pain development than those in the control group. In addition, the workers who had no lumbar support gained more benefits from the postural shift intervention regarding the prevention of low back pain development than those in the control group.
