Effect of office chair design features on lumbar spine posture, muscle activity and perceived pain during prolonged sitting

Abstract

Chair design features are typically compared using multiple seats, which can lead to confounding effects. Using a single chair, configurable to four designs (control, lumbar support, seat pan tilt and scapular relief), we investigated the effect of chair design on spine posture and movement, muscle activity and perceived pain in a sample of 31 asymptomatic adults. A total of 39% of the population were classified as pain developers, having significantly higher peak pain levels across most body regions. The lumbar support and seat pan tilt condition resulted in more neutral spine and pelvic postures. Greater muscle activity was found in the seat pan condition and non-pain developers displayed lower spine muscle activation levels overall. Despite some improvements in spine posture, sitting-induced pain was present in the study sample at similar proportions to those reported previously. Future studies may consider investigating interventions targeted to sitting-induced pain developers as opposed to the general population.

Practitioner summary: Four office chair configurations were tested. The lumbar support and seat pan tilt conditions resulted in the most neutral back posture but did not mitigate the clinically significant levels of sitting-induced pain experienced by a large portion of the tested sample. Future work should target interventions to these individuals.

Keywords:

• Office chair design
• sitting
• posture
• EMG
• spine movement

Acknowledgements

The test chair used in this study was built by CoreChair Inc. in accordance with our specific design criteria. Materials, time and engineering support were donated by the company and are gratefully acknowledged.

Disclosure statement

The authors declare no relevant financial or non-financial conflicts of interest to report.

Additional information

Funding

This work was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant; JPC is the Tier I Canada Research Chair in Spine Biomechanics and Injury Prevention and DED was supported by a Doctoral Research Award from the Canadian Institutes of Health Research.