Table Of ContentErgonomics in Computerized Offices
Ergonomics in
Computerized
Offices
Etienne Grandjean
Former Director of the Department of Ergonomics and
Hygiene, Swiss Federal Institute of Technology, Zürich
Taylor & Francis
London • New York (cid:127) Philadelphia
1987
UK Taylor & Francis Ltd, 1 Gunpowder Square, London EC4A 3DE
USA Taylor & Francis, 1900 Frost Road, Suite 101,
Bristol, PA 19007
This edition published in the Taylor & Francis e-Library, 2003.
Copyright © E.Grandjean 1987
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any
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the copyright owner and publishers.
British Library Cataloguing in Publication Data
Grandjean, E.
Ergonomics in computerized offices.
1. Video display terminals—Human
factors
I. Title
004.7´7 TK7882.16
ISBN 0-203-48975-6 Master e-book ISBN
ISBN 0-203-79799-X (Adobe eReader Format)
ISBN 0-85066-349-0 (Print Edition)
ISBN 0-85066-350-4 Pbk
Library of Congress Cataloging in Publication Data
Grandjean, E. (Etienne)
Ergonomics in computerized offices.
Bibliography: p.
Includes index.
1. Office practice—Automation—Psychological
aspects. 2. Video display terminals—Hygienic aspects.
3. Human engineering. I. Title.
HF5547.5.G693 1987 651.8´01´9 86–14588
ISBN 0-85066-349-0
ISBN 0-85066-350-4 (pbk.)
Cover d esign by Russell Beach
Foreword
Harry L.Davis
President of the International Ergonomics Association, past
President of the Human Factors Society and co-founder of one of
the earliest Ergonomics Practitioner Organizations in industry, at
the Eastman Kodak Company.
Other than the invention of the steam engine by Watt and the
consequent mechanization and industrialization of human work,
perhaps no single technological advancement in how work is
organized and performed has caused as much concern among
humans, and their social and technical organizations, as the
invention and subsequent proliferation of the computer. The
computer is totally changing the way humans collect and
manipulate data. It has ushered in the information age. In offices,
it is completely changing the way work and work groups are
organized. It is changing the very workplace in which people
perform their daily work; and it is that workplace, that working
environment, and those working humans that this book addresses.
With the extensively researched and factual information that is
presented in this book, ergonomists and engineers can design the
working environment and the workplace to conform to human
needs and human capabilities. Thus will be created a work situation
that is more comfortable, pleasant, productively efficient and less
stressful.
The author of this book, Professor Etienne Grandjean, was one
of the early pioneers in researching human capabilities and
limitations within industry, and applying that knowledge to the
design of industrial work situations. He has also been a pioneer in
researching and applying these human requirements to the design
of automated offices. This book is an important contribution for the
practitioners of ergonomics worldwide, as have many books
Professor Grandjean has previously published. Workers worldwide
will benefit from the improved design of automated offices brought
about by the use of data and methods contained herein.
v
Contents
Foreword by Professor Harry Davis v
1 The present metamorphosis of offices 1
2 VDT jobs seen through ergonomic-tinted spectacles 6
3 Physical characteristics of VDTs 10
4 Vision 16
4.1. The visual system 16
4.2. Accommodation 19
4.3. The aperture of the pupil 22
4.4. The adaptation of the retina 23
4.5. Eye movements 24
4.6. Visual capacities 25
4.7. Physiology of reading 28
5 Ergonomic principles of lighting in offices 32
5.1. Light measurement and light sources 32
5.2. Illumination level 36
5.3. Spatial balance of surface luminances 40
5.4. Temporal uniformity of lighting 46
5.5. Appropriate lights 47
6 Visual strain and photometric characteristics of
VDTs 55
6.1. Eye complaints of VDT operators 55
6.2. Photometric characteristics of displays 65
6.3. Equipment and methods to measure photometric
qualities of VDTs 66
6.4. Oscillating luminances of characters 69
6.5. Sharpness of characters 73
6.6. Character contrasts 76
6.7. Stability of characters 79
6.8. Reflections on screen surfaces 82
6.9. Size of characters and typeface 86
6.10. Dark versus bright characters 91
vii
viii Contents
7 Ergonomic design of VDT workstations 96
7.1. Constrained postures are long-lasting static efforts
for the muscles involved 96
7.2. Body size and the design of workstations for
traditional office jobs 101
7.3. Field studies on musculoskeletal troubles of office
employees 107
7.4. Postures, workstation characteristics and physical
discomfort 112
7.5. Orthopaedic aspects of the sitting posture 119
7.6. Ergonomic design of office chairs 130
7.7. VDT workstation design: preferred settings and
their effects 135
7.8. The VDT keyboard 150
7.9. Arrangement of work surfaces in computerized
offices 154
8 Noise 157
9 Occupational stress, work satisfaction and job
design 167
9.1. Occupational stress 167
9.2. Job satisfaction versus boredom 170
9.3. Alleged stress among VDT operators 173
9.4. Job design 185
10 Radiation, electrostatic fields and alleged health
hazards 193
10.1. Electromagnetic radiation emission from VDTs 193
10.2. Electrostatic fields 196
10.3. Skin rashes 198
10.4. Alleged cataracts 200
10.5. Alleged reproductive hazards due to VDT work 202
11 Recommendations for VDT workstations 206
11.1. Lighting 206
11.2. Photometric qualities of VDTs 207
11.3. Ergonomic design of office furniture and keyboards 208
11.4. Job design for VDT operators 209
References 211
Index 223
Author’s acknowledgement
My thanks are due to Frau Ilse Neur-Fannenböck for correcting my
english and typing the manuscript.
