Effects of a Dynamic Chair on Chair Seat Motion and Trunk Muscle Activity during Office Tasks and Task Transitions
Department of Orthopaedics and Traumatology, University Hospital Basel, 4031 Basel, Switzerland
Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland
Department of Sport, Exercise and Health, University of Basel, 4052 Basel, Switzerland
Department of Intervention Research in Exercise Training, German Sport University Cologne, 50933 Köln, Germany
Author to whom correspondence should be addressed.
Int. J. Environ. Res. Public Health 2018, 15(12), 2723; https://doi.org/10.3390/ijerph15122723
Received: 5 November 2018 / Revised: 28 November 2018 / Accepted: 29 November 2018 / Published: 3 December 2018
(This article belongs to the Section Health Behavior, Chronic Disease and Health Promotion)
Employing dynamic office chairs might increase the physical (micro-) activity during prolonged office sitting. We investigated whether a dynamic BioSwing® chair increases chair sway and alters trunk muscle activation. Twenty-six healthy young adults performed four office tasks (reading, calling, typing, hand writing) and transitions between these tasks while sitting on a dynamic and on a static office chair. For all task-transitions, chair sway was higher in the dynamic condition (p < 0.05). Muscle activation changes were small with lower mean activity of the left obliquus internus during hand writing (p = 0.07), lower mean activity of the right erector spinae during the task-transition calling to hand writing (p = 0.036), and higher mean activity of the left erector spinae during the task-transition reading to calling (p = 0.07) on the dynamic chair. These results indicate that an increased BioSwing® chair sway only selectively alters trunk muscle activation. Adjustments of chair properties (i.e., swinging elements, foot positioning) are recommended.