The ability of non-computer tasks to increase biomechanical exposure variability in computer-intensive office work

Abstract

Postures and muscle activity in the upper body were recorded from 50 academics office workers during 2 hours of normal work, categorised by observation into computer work (CW) and three non-computer (NC) tasks (NC seated work, NC standing/walking work and breaks). NC tasks differed significantly in exposures from CW, with standing/walking NC tasks representing the largest contrasts for most of the exposure variables. For the majority of workers, exposure variability was larger in their present job than in CW alone, as measured by the job variance ratio (JVR), i.e. the ratio between min–min variabilities in the job and in CW. Calculations of JVRs for simulated jobs containing different proportions of CW showed that variability could, indeed, be increased by redistributing available tasks, but that substantial increases could only be achieved by introducing more vigorous tasks in the job, in casu illustrated by cleaning.

Abstract

Practitioner Summary: Too little exposure variation is a general concern in computer-intensive office work. This study shows, using a novel metric, that available NC tasks can, indeed, increase variation compared to doing only CW, but also that a substantial increase in variation requires introducing more vigorous tasks such as cleaning.

Keywords::

• task contrasts
• exposure variation
• posture
• EMG

Acknowledgements

The authors are grateful for the administrative support from the Federal University of São Carlos, including the servers who have participated as volunteers.

Supplementary material

Supplementary material may be viewed online at http://dx.doi.org/10.1080/00140139.2014.965753

Notes

^1. Email: [email protected]

^2. Email: [email protected]

^3. Email: [email protected]

^4. Email: [email protected]

Additional information

Funding

This work was supported by the São Paulo Research Foundation (FAPESP) – Grants 2011/03557–0 and 2012/06175–4 – and by the Swedish Research Council for Health, Working Life and Welfare (Forte Dnr. 2009–1761).