Abstract
OBJECTIVE: This study evaluated the effectiveness of the promotion of postural shift intervention using a dynamic seat cushion on the 6-month incidence of neck and low-back pain among high-risk office workers. METHODS: In a cluster-randomized controlled trial (RCT), 133 office workers were randomly assigned, at cluster level, to intervention (N=67) and control (N=66) groups. The intervention group received a dynamic seat cushion to encourage postural shifts during sitting, while the control group received a placebo seat pad. Primary outcomes were 6-month incidence of neck and low-back pain. Secondary outcomes included sitting discomfort, pain intensity, disability, and trunk muscle performance. Analyses utilized Cox proportional hazard models. RESULTS: During the 6-month period, 15% of participants in the intervention group developed neck pain and 10% developed low-back pain. For the control group, this was 65% and 59%, respectively. Hazard rate (HR) ratios, after adjusting for biopsychosocial factors, indicated a protective effect of the intervention for neck pain [HR(adj) 0.19, 95% confidence interval (CI) 0.09-0.39, P<0.001] and low-back pain (HR(adj) 0.16, 95% CI 0.07-0.35, P<0.001). The intervention group demonstrated a significant reduction in sitting discomfort and improvement in trunk muscle performance compared to the control group (P<0.05). However, the intervention did not reduce pain and disability in individuals experiencing pain compared to the control group. CONCLUSIONS: The dynamic seat cushion effectively reduced the incidence of neck and low-back pain by promoting postural shifts. These findings suggest that the key factor in reducing the risk of developing neck and low-back pain is the facilitation of postural shifts during sitting, which can potentially be achieved with other dynamic interventions designed to reduce prolonged and static sitting among office workers.