title: 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.
authors.affiliation: a Laboratory of Clinical and Occupational Kinesiology (LACO), Department of Physical Therapy , Federal University of São Carlos , Washington Luiz Road, km 235, SP310, 13565-905 São Carlos , Brazil.
authors.forename: Dechristian França
authors.initials: DF
authors.lastname: Barbieri
authors.forename: Divya
authors.initials: D
authors.lastname: Srinivasan
authors.forename: Svend Erik
authors.initials: SE
authors.lastname: Mathiassen
authors.forename: Helen Cristina
authors.initials: HC
authors.lastname: Nogueira
authors.forename: Ana Beatriz
authors.initials: AB
authors.lastname: Oliveira
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003201:Computers; D004576:Electromyography; D006804:Ergonomics; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D011187:Posture; D064171:Superficial Back Muscles / Q000502:physiology; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology; D014937:Work / Q000502:physiology*; D014953:Wrist / Q000502:physiology
keywords: EMG; exposure variation; posture; task contrasts