The effects of chair intervention on lower back pain, discomfort and trunk muscle activation in office workers: a systematic review.

Objectives. The chair is a standard piece of workstation equipment in an office. Previous studies showed that a suitable chair may reduce musculoskeletal symptoms. This review investigated the effect of chair intervention on lower back pain (LBP), discomfort and trunk muscle activation among office workers. Methods. Five electronic databases from 1980 to May 2020 were searched for relevant randomized and non-randomized controlled trials. The methodological quality of the included studies was assessed using the 13-item Cochrane risk of bias tool. Quality of evidence was assessed and rated according to Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines. Results. Two randomized controlled trials, 10 repeated-measures studies and two prospective cohort studies were included in this review. Nine studies were rated as high quality. The results indicated very low-quality to low-quality evidence for the conflicting effect of chair intervention on pain and discomfort reduction as well as trunk muscle activation among office workers. When stratified by chair type, the level of evidence for health benefits derived from any type of chair was still of very low to low quality. Conclusion. Unless supplementary high-quality studies provide different evidence, chair interventions are not recommended to reduce LBP or discomfort and activate trunk muscles.