Comfort in Using Hand Tools
Theory, Design and Evaluation
ter verkrijging van de graad van doctor aan de Technische Universiteit Delft, op gezag van de Rector Magnificus Prof. dr. ir. J.T. Fokkema, voorzitter van het College van Promoties, in het openbaar te verdedigen op 19 januari 2007 om 12.30 uur door Lottie Francisca Maria KUIJT‐EVERS doctorandus in de bewegingswetenschappen geboren te Weert
Dit proefschrift is goedgekeurd door de promotoren: Prof. dr. P. Vink Prof. dr. M.P. de Looze
Samenstelling promotie commissie: Rector Magnificus, voorzitter Prof. dr. P. Vink, Technische Universiteit Delft, promotor Prof. dr. M.P. de Looze, Vrije Universiteit Amsterdam, promotor Prof. dr. C.J.P.M. de Bont, Technische Universiteit Delft Prof. dr. J. van Dieën, Vrije Universiteit Amsterdam Prof. ir. D.J. van Eijk, Technische Universiteit Delft Prof. dr. C.J. Overbeeke, Technische Universiteit Eindhoven Dr. L. Sperling, Lund University, Sweden TNO Kwaliteit van Leven Arbeid Cover drawings by Tom Kuijt Printing PlantijnCasparie, Amsterdam ISBN‐10: 90‐5986‐218‐X ISBN‐13: 978‐90‐5986‐218‐X © 2006 Lottie F.M. Kuijt‐Evers All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage or retrieval system, without permission from the author.
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Introduction State of science Identifying factors of comfort in using hand tools 5 19 61
Identifying predictors of comfort and discomfort in using hand tools Comfort predictors for different kinds of hand tools: differences and similarities An application of the QFD to the design of comfortable screwdrivers Association between objective and subjective measurements of comfort and discomfort in using hand tools Epilogue
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Chapter 8 Summary Samenvatting Dankwoord Publications
About the author
Hand tools like scissors, forks and knives are used daily by almost all European citizens. A large proportion of these European citizens also use hand tools (like hammers, pliers, chisels, and trowels) during their work, as non‐powered hand tools constitute an important element of work and production systems (European Agency for Safety and Health at Work, 2000). Some jobs cannot be done without hand tools, like the work of carpenters, surgeons, cooks and maintenance workers. Consequently many tools are sold yearly. For instance Bahco Tools, an important manufacturer of non‐powered hand tools, has a turnover of 300 MEur per year, selling in 1998 its 100.000.000th wrench. (http://www.selligent.com/open.asp?file=1118). Despite the frequent use of hand tools by many people over many, many years, the design of hand tools did hardly change during the last century (Haapalainen et al., 1999/2000). For instance, the trowel still looks the same as years ago (Figure 1.1). New materials (like plastics) have become available for hand tool manufacturing and provide the possibility to change the design, but these materials are hardly applied. Figure 1.1 Collection of old trowels in a hand tool museum (Maison de l’Outil et de la Pensée Ouvriere, Troyes, France).
Chapter 1 For several reasons, it is important to reconsider the traditional design of hand tools, that is to avoid feelings of discomfort during the job, to reduce musculoskeletal disorders on a longer term, to increase the workers’ productivity and to ...