The Impact of Chair Type on Quality Sitting Behaviours in a Prolonged Sitting Exposure

The increasing demand of low activity occupations to involve prolonged sitting may cause an increase in the risk of musculoskeletal injuries. Due to this demand, this study investigated the effect of two different office chairs on quality sitting behaviours. Forty participants performed two 1hr sitting trials involving four 15min tasks (completing questionnaires, typing, and mouse maneuvering for 5min each) while seated in a fixed or dynamic chair. Muscle activation, kinematics, chair kinetics, and self-reported pain were collected. The dynamic chair improved quality sitting behaviours: muscle co-activation decreased in males; seatback relative TPP and LPP increased in males; relative TPA was significantly higher; and less participants were pain-developers. The dynamic chair may reduce low static trunk muscle activity, increase TPA with the dynamic chair, which may contribute to the delayed onset of self-reported pain; may drive seated behaviour change, thereby reducing MSD risk without requiring knowledge or action of the user.