PROCID Recommendations for Healthier Computer Work Swedish Version

In: Caldenfors, D. Eklund, J. Kiviloog, L. (Eds), Humans in a Complex Environment: Proceedings of the 34th Annual Congress of the Nordic Ergonomic Soc...
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In: Caldenfors, D. Eklund, J. Kiviloog, L. (Eds), Humans in a Complex Environment: Proceedings of the 34th Annual Congress of the Nordic Ergonomic Society, 1-3 October 2002, Kolmården, Sweden Volume II – ISBN: 91-7373-444-6

PROCID Recommendations for Healthier Computer Work Swedish Version L. Sandsjö 1,2 , R. Kadefors 1,3 , U. Lundberg 4 , and the PROCID group 1 National Institute for Working Life/West, P.O. Box 8850, SE-402 72 Göteborg,

SWEDEN 2 Signals and Systems, Chalmers University of Technology, Göteborg, SWEDEN 3 Department of Human Factors Engineering, Chalmers University of Technology,

Göteborg, SWEDEN 4 Department of Psychology, Stockholm University, Stockholm, SWEDEN

E-mail: [email protected] Abstract PROCID (PRevention of muscle disorders in Operation of Computer Input Devices) was a European Concerted Action, ending in March 2001, that for three years brought ten research organisations from Denmark, Italy, Sweden and Switzerland together to carry out research on muscle disorders in the upper extremities from computer work. One specific aim of the threeyear activity was to present the results of the research activities in such a way that they could be of practical help to end-users in preventing computer-related muscle disorders from developing. The result is a set of six recommendations aimed towards operators and employers, as well as manufacturers of computer equipment. The recommendations are scientifically based and should be considered as supplementary to existing guidelines. This paper establishes an official Swedish version of the “PROCID Recommendations for healthier computer work”. Keywords Computer work, musculoskeletal disorders, recommendations

1 INTRODUCTION In the European Community health statistics indicate an increased incidence of work related muscular disorders among computer users (e.g. Wigeaus Tornqvist et al., 2001). Problems include aches and pain in the neck and shoulder region, and in the upper extremities. The high prevalence has been associated with task related factors such as constrained posture and poor ergonomic design of the work place, as well as of input devices. Stress-related factors are also important determinants for the adverse muscular effects. In order to address these problems, a consortium made up of ten European organisations was formed and applied for funds from the European Commission as a concerted action under the name of PROCID (Prevention of muscle disorders in Operation of Computer Input Devices). The consortium was multidisciplinary, engaging physiologists, medical doctors, ergonomists, psychologists and engineers. PROCID was coordinated by the National Institute for Working Life/West in Göteborg,

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In: Caldenfors, D. Eklund, J. Kiviloog, L. (Eds), Humans in a Complex Environment: Proceedings of the 34th Annual Congress of the Nordic Ergonomic Society, 1-3 October 2002, Kolmården, Sweden Volume II – ISBN: 91-7373-444-6

Sweden, and ran from April 1998 to March 2001. A list of the participating organisations is given in Table 1. Table 1. The PROCID consortium: Country, organisations and contact persons. Country

Organisation

Contact person(s)

Denmark

National Institute of Occupational Health, Copenhagen

H. Christensen, G. Sjøgaard

Italy

Politecnico di Torino, Torino

R. Merletti

Salvatore Maugeri Foundation, IRCCS Rehabilitation Institute R. Colombo of Veruno, Veruno Sweden

Switzerland

Department Göteborg

of

Orthopaedics,

University

of

Göteborg, P. Herberts

Department of Physiology, University of Göteborg, Göteborg

Å. Vallbo

Department of Psychology, Stockholm University, Stockholm

U. Lundberg

National Institute for Working Life/West, Göteborg (co-ordinator)

R. Kadefors, L. Sandsjö

Department of Rheumatology and Institute of Physical Medicine, University Hospital Zurich, Zurich

A. Klipstein

Institute for Hygiene and Applied Physiology/ETH, Zurich

T. Läubli

Institute for Signal and Information Processing/ETH, Zurich

G. Moschytz, P. Wellig

1.1 Approach The starting point in the project was the so-called Cinderella hypothesis, saying that there are groups of muscle fibres, low-threshold motor units, which are always activated when a muscle is loaded and stay continuously active for as long as the muscle is engaged (Hägg, 1991). If the activation does not allow relaxation and recovery, there is an increased risk for the muscle fibres, in the long run, to be damaged; causing chronic pain that may be difficult to treat medically. Therefore, the primary approach followed in the project was to monitor recruitment and firing patterns of motor-units in a wide variety of situations relevant to computer work, involving both physical and mental stress.

2 THE PROJECT The first half of the three-year long project was mainly devoted to methodological development, whereas the second half was applied research making use of the methodological achievements. The activities were concentrated to the following three areas: Development of fine wire techniques for the multi-lead intramuscular signal acquisition Methodology for motor-unit identification and tracking under dynamic conditions Experimental set-up and organisation of well-defined studies of computer work

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In: Caldenfors, D. Eklund, J. Kiviloog, L. (Eds), Humans in a Complex Environment: Proceedings of the 34th Annual Congress of the Nordic Ergonomic Society, 1-3 October 2002, Kolmården, Sweden Volume II – ISBN: 91-7373-444-6

At the midterm of the project, a symposium was held to gather researchers from the PROCID consortium and noted invited researchers in order to summarise existing knowledge of relevant basic phenomena and methodologies needed to study muscular activation patterns at the motor-unit level. Following this first PROCID symposium, “Muscular disorders in computer users: Mechanisms and models” (Christensen and Sjøgaard, 1999) a number of abstracts presented at this event were invited as full papers for special issues of the Journal of Electromyography and Kinesiology (Kadefors and Sjøgaard, 2001) and European Journal of Applied Physiology (Sjøgaard et al., 2000). At the end of the project, a second PROCID symposium, “Prevention of muscle disorders in computer users: Scientific basis and recommendations”, was held (Sandsjö and Kadefors, 2001) following a similar procedure. This time the focus was on studies of computer work and the post-event publications were made in special issues of Work&Stress (Lundberg and Christensen, 2002) and International Journal of Industrial Ergonomics (Kadefors and Läubli, 2002). Apart from the scientific reporting, the need for interpretation of the results into practical recommendations aimed directly to end users, i.e. computer users, employers and manufacturers of computer equipment, were identified. This process started with a series of meetings where the PROCID group discussed the practical implications of the results, which were summarised in a draft document of eight recommendations. In order to test the applicability of these recommendations in everyday situations, the PROCID group arranged a "PROCID Workshop on Healthier Computer Work" as a part of the 2nd PROCID symposium, where the recommendations were presented and discussed among international scientists and practitioners within the field. From the input during this workshop the recommendations were somewhat rephrased and condensed into six "PROCID Recommendations for Healthier Computer Work".

3 PROCID RECOMMENDATIONS FOR HEALTHIER COMPUTER WORK The research carried out under the PROCID umbrella demonstrated that there are motor-units that exhibit precisely those activation patterns that, according to the theory, constitute an elevated risk, under a wide variety of conditions. Physical load, movement patterns and psychological stress during work have been taken into account. The six recommendations drawn from this work and shown in the original form in Table 2, are directed towards the design of the workplace as well as individual and organisational behaviour to deal with these problems (Christensen et al., 2001; Sandsjö et al., 2001; Kadefors and Läubli, 2002). Table 3 presents the official Swedish translation of the six recommendations. The "PROCID Recommendations for Healthier Computer Work" should be seen as a complement to existing standards, norms and practice concerning working conditions in computer users (see Toomingas (Internet, 2001) for a summary in both English and Swedish). The PROCID recommendations are relevant to all professionals who spend a large portion of the workday in front of the computer. They address employers as well as the users themselves. These recommendations are based on results arrived at in the PROCID project, and in PROCID-related research, as documented in international publications in peer-reviewed scientific journals. It should be emphasized that the PROCID recommendations are based on scientific achievements relevant to the theoretical framework presented. It is clear that there are important areas that need further scrutiny in order to arrive at a full understanding of how exposure to computer work links to muscular disorders. In that sense, the recommendations are preliminary. On the other hand it is the responsibility of the

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In: Caldenfors, D. Eklund, J. Kiviloog, L. (Eds), Humans in a Complex Environment: Proceedings of the 34th Annual Congress of the Nordic Ergonomic Society, 1-3 October 2002, Kolmården, Sweden Volume II – ISBN: 91-7373-444-6

scientific community to give advice to practitioners at any time, on the basis of current knowledge. Table 2.

The PROCID recommendations for healthier computer work with risk factors.

Recommendation

Risk Factor

1. Operators must limit repetitive finger movements and constrained postures. There must be a selection of input devices including possibilities for non-hand input alternatives.

Fast repetitive finger movements activate cocontraction in neck and upper limb muscles. Lack of variation in activation of motor-units. i

2. Operators must avoid double clicking.

Fast motor unit firing induces peak muscle load. ii

3. Operators with pain should not just switch mouse hand to avoid the pain, but should make use also of other input alternatives.

Contralateral activity may occur. iii

Lack of motor unit silence during work. Mental 4. Breaks from computer work must be load activates the same motor-units, as does frequent and allow for mental relaxation. Operators must be educated how to achieve full computer operation. iv mental and muscular relaxation. 5. Operators must be qualified to fit the tasks to Pain/discomfort and/or fatigue do not in itself their ability and pay attention to signs of prevent muscle activity. v fatigue, pain and/or discomfort. Employers must be alert to such reporting and take actions - for instance by introducing technical and/or organisational changes. 6. Employers and operators must pay attention to factors contributing to stress in the work situation and take actions to limit stress.

Mental load, distress and/or time pressure increase muscle activity. vi

Acknowledgements This work was undertaken as an activity within the project, “Prevention of muscle disorders in operation of computer input devices (PROCID)”, a Concerted Action financed under the European Union research programme BIOMED-2 (BMH-98-2902). The contributions of all consortium members are gratefully acknowledged.

i

Reported in: Rissén et al. (2000); Sandsjö et al. (2000); Schnoz et al. (1999, 2000); Sjøgaard et al. (2000) ii Reported in: Sjøgaard et al. (2001); Søgaard et al. (2001) iii Reported in: Søgaard et al. (2001) iv Reported in: Birch et al. (2000); Jensen et al. (2000); Forsman et al. (1999, 2000, 2002); Kadefors et al. (1999); Kitahara et al. (2000); Søgaard et al. (2001); Thorn et al. (2002) v Reported in: Birch et al. (2000); Lundberg et al. (1999); Rissén et al. (2000); Sandsjö et al. (2000); Sjøgaard et al. (2000) vi Reported in: Lundberg et al. (1999); Rissén et al. (2000); Sandsjö et al. (2000); Sjøgaard et al. (2000)

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In: Caldenfors, D. Eklund, J. Kiviloog, L. (Eds), Humans in a Complex Environment: Proceedings of the 34th Annual Congress of the Nordic Ergonomic Society, 1-3 October 2002, Kolmården, Sweden Volume II – ISBN: 91-7373-444-6

Table 3.

Official Swedish version of the PROCID recommendations for healthier computer work with risk factors.

Rekommendation

Riskfaktor

1. Användare måste begränsa repetitiva fingerrörelser och onaturliga kroppsställningar. Det måste finnas olika typer av styr- och inmatningsdon som inkluderar icke handstyrda alternativ.

Snabba repetitiva fingerrörelser leder till samtidig kontraktion av musklerna i nacke/skuldra och arm. De motoriska enheterna engageras på ett ensidigt sätt. i

2. Användare ska undvika att dubbelklicka.

Täta aktiveringar av motoriska enheter medför toppar i muskelbelastningen. ii

3. Användare som har ont bör inte bara byta mushand för att undvika smärta, utan bör även använda andra inmatningsmöjligheter.

Muskelaktivering kan ske på båda sidor även om bara en arm används. iii

4. Datorarbete måste inrymma ofta förekommande perioder av vila som möjliggör även mental avslappning. Användare måste utbildas i hur de kan uppnå fullständig mental och muskulär avslappning.

Brist på avbrott i aktiveringen av motoriska enheter. Mental belastning aktiverar samma motoriska enheter som datorinmatning. iv

5. Användaren måste ges möjlighet att anpassa arbetsinnehållet till sin förmåga och vara uppmärksam på tecken till trötthet, smärta och/eller obehag. Arbetsgivaren måste vara lyhörd för sådana signaler och vidta åtgärder – t ex genom att genomföra tekniska och/eller organisatoriska förändringar.

Smärta/obehag och/eller trötthet är i sig inget skydd mot ogynnsam muskelaktivitet. v

6. Arbetsgivare och användare måste vara uppmärksamma på faktorer som bidrar till stress i arbetssituationen och vidta åtgärder för att minska stressen.

Mental belastning, obehag och/eller tidspress leder till ökad muskelaktivitet. vi

Footnotes i-vi refer to the previous page and are the same as in Table 2.

References Birch, L., Christensen, H., Arendt-Nielsen, L., Graven-Nielsen, T., Søgaard, K. (2000): The influence of experimental muscle pain on motor unit activity during low level contraction. European Journal of Applied Physiology, 83, 200-206. Christensen, H., and Sjøgaard, G. (Eds.) (1999): Muscular Disorders in Computer Users: Mechanisms and Models. National Institute of Occupational Health, Copenhagen, Denmark (ISBN87-7904-038-1). 215 pages. Christensen, H., Søgaard, K., Sjøgaard, G., and the PROCID group (2001): Recommendations for healthier computer work based on scientific evidence provided under “PROCID”. In: Musculoskeletal research at work: From problem analysis to effective interventions. Fourth International Conference on Prevention of Work-Related Musculoskeletal disorders - PREMUS, Amsterdam, The Netherlands, 193. Forsman, M., Birch, L., Zhang, Q., Kadefors, R. (2001): Motor-unit recruitment in the trapezius muscle with special reference to coarse arm movements. Journal of Electromyography and Kinesiology, 11,207-216. Forsman, M., Kadefors, R., Zhang, Q., Birch, L., Palmerud, G. (1999): Motor-unit recruitment in the trapezius muscle during arm movements and in VDU precision work. International Journal of Industrial Ergonomics, 24, 619-630.

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Forsman, M., Taoda, K., Thorn, S., Zhang, Q. (2002): Motor-unit recruitment during long-term isometric and wrist motion contractions: a study concerning muscular pain development in computer operators. International Journal of Industrial Ergonomics (in press). Hägg, G.M., (1991): Static work and myalgia – a new explanation model. In: Andersson, P.A.., Hobart, D.J., Danoff, J.V. (Eds): Electromyog kinesiol. Elsevier Science, Amsterdam, 115-119. Jensen, B.R., Pilegaard, M., Sjøgaard, G. (2000): Motor unit recruitment and rate coding in response to fatiguing shoulder abductions and subsequent recovery. European Journal of Applied Physiology, 83, 190-199. Kadefors, R., Forsman, M., Zoega, B., Herberts, P. (1999): Recruitment of low threshold motor-units in the trapezius muscle in different static arm positions. Ergonomics, 42, 359-375. Kadefors, R., and Läubli, T. (2002): Editorial. Muscular disorders in computer users: Introduction. Special Issue: International Journal of Industrial Ergonomics, (in press). Kadefors, R., and Sjøgaard, G. (2001): Editorial. Motor-unit recruitment and firing patterns, and their role in development of chronic muscular pain: analysis methods, mechanisms and models. Special Issue: Journal of Electromyography and Kinesiology, 11, 149. Kitahara, T., Schnoz, M., Läubli, T., Wellig, P., Krueger, H. (2000): Motor-unit activity in the trapezius muscle during rest, while inputting data, and during fast finger tapping. European Journal of Applied Physiology, 83, 181-189. Lundberg, U., and Christensen, H. (2002): Editorial. Musculoskeletal problems as a result of work organization, work tasks and stress during computer work. Special Issue:Work&Stress, (in press). Lundberg, U., Elfsberg Dohns, I., Melin, B., Sandsjö, L., Palmerud, G., Kadefors, R., Ekström, M., Parr, D. (1999): Psychophysiological stress responses, muscle tension and neck and shoulder pain among supermarket cashiers. J Occup Health Psychology, 4:3, 245-255. Rissén, D., Melin, B., Sandsjö, L., Dohns, I., Lundberg, U. (2000): Surface EMG and psychophysiological stress reactions among female employees at supermarkets. European Journal of Applied Physiology, 83, 215-222. Sandsjö, L., and Kadefors, R. (Eds.) (2001): Prevention of Muscle Disorders in Computer Users: Scientific Basis and Recommendations. National Institute for Working Life, Göteborg, Sweden (ISBN 91-7045-590-2). 260 pages. Sandsjö, L., Kadefors, R., Zennaro, D., and the PROCID group. (2001): PROCID Recommendations for healthier computer work. In HCI International 2001 – 9th International Conference on HumanComputer Interaction, 5-10 August 2001, New Orleans, Louisiana, USA, 295-297. Sandsjö, L., Melin, B., Rissén, D., Dohns, I., Lundberg, U. (2000): Trapezius muscle activity, neck and shoulder pain, and subjective experiences during monotonous work in women. European Journal of Applied Physiology, 83, 235-238. Schnoz, M., Läubli, T., Krueger, H. (2000): Co-activity of the trapezius and upper arm muscles with finger tapping at different rates and trunk postures. European Journal of Applied Physiology, 83, 207214. Schnoz, M., Läubli, T., Weiss, J.A., Krueger, H. (1999): Aktivierung der Finger- und Trapezmuskulatur bei repetitiven Kurz- und Langzeit-Fingerbewegungen. Zeitung für Arbeitswissenschaft, 53, 131-138. Sjøgaard, G., Lundberg, U., Kadefors, R. (2000): The role of muscle activity and mental load in the development of pain and degenerative processes at the muscle level during computer work. Special Issue: European Journal of Applied Physiology. 83, 99-105. Sjøgaard, G., Søgaard, K., Finsen, L., Olsen, H.B., Christensen, H. (2001): Doublets in motor unit activity of human forearm muscle during simulated computer work. Acta Physiologica and Pharmalogica Bulgarica, 26(1/2), 83-85. Søgaard, K., Sjøgaard, G., Finsen, L., Olsen, H.B., Christensen, H. (2001): Motor unit activity during stereotyped finger tasks and computer mouse work. Journal of Electromyography and Kinesiology, 11, 197-206. Thorn, S., Forsman, M., Zhang, Q., Taoda, K. (2002): Low-threshold motor unit activity during a onehour contraction in the trapezius muscle. International Journal of Industrial Ergonomics, (in press). Toomingas, A. (Internet, first published 2001): Tema: Datorarbete. (in Swedish) http://www.niwl.se/datorarbete/ Toomingas, A. (Internet, first published 2001): Theme: Computer Work (in English) http://www.niwl.se/datorarbete/default_en.asp Wigaeus Tornqvist, E., Eriksson, N., Bergqvist, U. (2001): Risks factors at computer and office workplaces. In: Marklund, S., (Eds.), Worklife and health in Sweden 2000. Solna, Sweden: National Institute for Working Life and Swedish Work Environment Authority, 189-213.

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