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Effects of training to implement new tools and working methods to reduce knee load in floor layers
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Applied Ergonomics 38 (2007) 655–665 www.elsevier.com/locate/apergo
Effects of training to implement new tools and working methods to reduce knee load in floor layers Lilli Kirkeskov Jensen, Claus Friche Department of Occupational Medicine, Sygehus Viborg, Resenvej 25, DK 7800 Skive, Denmark Received 15 December 2004; accepted 6 March 2006
Abstract The purpose was to measure the effect of a participatory ergonomics implementation strategy consisting of information, education, and facilitation on the use of new tools and working methods in the floor laying trade. Floor layers (n ¼ 292) were trained in using new working methods. The effects were evaluated by using questionnaires, interviews, and assessments of quality and productivity. Following the training, 43% had used the new working methods weekly/daily compared to 11% before. There was a reduction in the degree of selfreported pain in the knees among the floor layers using the new working methods weekly or daily compared to those using them never or occasionally. The musculoskeletal complaints did not increase from any other region and the quality and the productivity of the work were not decreased. This indicates that within a 3-months perspective the implementation strategy succeeded. r 2006 Elsevier Ltd. All rights reserved. Keywords: Implementation; New working methods; Construction industry
1. Introduction In Denmark, 900 floor layers are members of the trade union, and 120 firms are members of the employers’ association, which covers about 90% of all floor layers in Denmark. Floor- and carpet layers (hereafter referred to collectively as floor layers) install linoleum, carpet, and vinyl floorings. Their work tasks include removal of old flooring, grinding, filling, installation of underlay, measuring and cutting materials, gluing, welding, installation of plastic skirting board, and transport. Earlier studies have shown that the floor layers spend more than half of their working day in knee-straining working positions (kneeling or squatting) (Ekstro¨m et al., 1983; Jensen et al., 2000b; Kivima¨ki et al., 1992; Thun et al., 1987). In earlier studies, floor layers were found to have an increased frequency of knee complaints and knee osteoarthritis compared to other trades in the construction industry (Holmstro¨m et al., 1995;
Corresponding author. Tel.: +45 89 27 48 50; fax: +45 89 27 48 79.
E-mail address: [email protected] (L.K. Jensen). 0003-6870/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.apergo.2006.03.008
Jensen et al., 2000b, c; Kivima¨ki et al., 1992; Thun et al., 1987). In Denmark since 1996, the trade union and the employers’ association have, through campaigns and regional meetings, tried to change the attitude of the trade and to make the workers supportive towards standing up when they work. During recent years, new tools have been introduced which make it possible to carry out some of the job tasks (such as gluing, filling, welding, up-cutting, and cutting of welding wire) from a standing working-position. Floor layers and teachers at the technical school for floor layers have tested the tools. The system is based on a telescopic stick, an intercostals fitting, and special fittings for these specific job tasks (gluing, filling, welding, and upcutting). The traditional and new working methods are illustrated in Fig. 1. However, in spite of such campaigns, and the development of the new tools, an investigation from 2000 found that only 13% of the floor layers had used the new working methods during the previous 12 months (Jensen and Kofoed, 2003). The floor layers reported that the reason for the lack of change was that the new methods needed to be learned, and that it was difficult to find time during a
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Fig. 1. (a) Floor layers. Gluing: working traditionally (left), and using new (right) working methods. (b) Floor layers. Filling: working traditionally (left), and using new (right) working methods.
busy working day to try new methods. They also reported that educational training was necessary. The floor layers in general were very sceptical, especially about taking advice from academics, and would only take suggestions or criticism from people who were experienced in their trade. They also reported that the tools were not satisfactory in use (Jensen and Kofoed, 2003). The 2000 study showed that implementation of new working-methods was very difficult, and this agreed with the findings of other studies (De Jong and Vink, 2002; Schneider, 2001; van der Molen, 2005). Schneider (2001) described four key factors in establishing an effective ergonomics programme: (i) strong management support, (ii) efficient assessment, (iii) effective training, and (iv) improvements to the physical work environment. The overall goal of this study has been to change the behaviour of floor layers, and thereby to implement the new working methods in the floor laying trade. Compared with the earlier study in 2000 (Jensen and Kofoed, 2003)the tools were much more developed, and there was more support from the employers and employees and their
organisations, since the project had funding to give one third of the floor layers in Denmark the tools and courses free of charge. Many researchers suggest a participatory approach to the development and implementation of new working methods and new tools to reduce physical demands at work (Haines et al., 2002; Moore and Garg, 1996, 1997; van der Molen, 2005; van der Molen et al., 2005; Vink et al., 1992). There is no single unifying model of participatory ergonomics, and an adjusted model has been constructed for this study. In earlier studies, seven levels have been described in the changing of behaviour in relation to an implementation strategy: (1) awareness of the physical work demands and health risks associated with the use/no use of ergonomic measures, (2) understanding of the ergonomic measures, (3) desire to provide or use the ergonomic measures, (4) intention to buy, hire or use the ergonomic measure, (5) ability to use the ergonomic measures, (6) gaining experience by using the ergonomic measure, and (7) continuing use of the ergonomic measures (van der Molen
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et al., 2005). In relation to these phases, the aim of the present study has been (1) to inform the workers and their employers about the new tools (where to buy, and how to use them) (2) to inform the workers about the tools and the health risk, comparing the conventional and the new working methods (3a) to show the new working methods to the floor layers, (3b) and thereby to convince the floor layers to use them, (4) to give the floor layers the tools (free of charge if they participated in a 2-day course, (5) to train them through a 2-days course in using the tools, (6) providing experience of using the new tools and methods during the training of the floor layers, (7) enabling them to continue using the new working methods after the courses. The main objective of this study is to investigate whether the implementation strategy has an effect on the use of the new working methods, and on the musculoskeletal complaints which occur, compared with using the conventional working methods. This objective was transferred into the following research questions: (1) Does the implementation strategy increase the frequency of floor layers using the new working methods? (2) Do the use of the new working methods reduce musculoskeletal complaints comparing floor layers who did change their working methods with those who did not. (3) Do the use of the new working methods results in more different health problems (e.g. musculoskeletal complaints from other regions)? (4) Are the new working methods as fast (i.e. as productive) as the traditional methods? (5) Is the quality of the work better, worse or the same as a result of using the new working methods? The hypothesis is that the implementation strategy would increase the use of the new working methods and thereby reduce the knee complaints among the floor layers and make the works go faster without reducing the quality of the work. 2. Material and methods In this study the participatory approach included the following phases: information-dissemination, policy making by trade union and employers’ association, information of employers and employees about the policy, the new working methods and the health risk, training of supervisors, training of floor layers, and evaluation, as shown in Table 1. 2.1. Information process In the Autumn of 2002, eight regional 2-h meetings were arranged by the trade union, the employers’ association, and a specialist teacher from the technical school in Viborg (which is the central technical school for floor layers in Denmark). The number of participants was 174 (91% floor layers and 9% employers). At the meetings, the new working methods were introduced in theory and in practise. An extensive and goal-directed written and oral presentation, including possibilities to become acquainted
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Table 1 The phases in the participatory ergonomics implementation strategy: from research to changing work-methods in the floor laying trade Information provided about health risks, based on relevant research Development of usable and acceptable tools Local meetings for 174 floor layers and their employers to provide information about: Health risks How to use the tolls Support (policy) from trade union and employers’ association Training by a specialist teacher Four 2-days courses for 38 floor layers (pilots) Training of supervisors Two-week course for expert floor layers (supervisors)
1996–2002 2000–2002 Autumn 2002
January 2003
Training of floor layers by supervisors at local technical schools around the country Two-day courses for 254 floor layers Provision of tools (free of charge) to the participants
February–June 2003
Base-line- study: First Questionnaire
February–June 2003
Evaluation: Second questionnaire Interviews Quality study Time-study
June–September 2003 June–September 2003 August–September 2003 August-September 2003
with the new working methods and tools, was made and distributed. Representatives of the employers’ association and the trade union at this meeting stated that they concurred in supporting the process, and wished the new working methods to be used. 2.2. Education of teachers and floor layers 2.2.1. Course for supervisors The training of the floor layers who would subsequently be used as teachers (hereafter referred to as ‘supervisors’) was considered necessary if the new working methods were to be communicated to, and accepted by, a large proportion of the floor layers. A total of 10 floor layers participated in a 2-week course in January 2003. They were chosen on the following criteria: they geographically represented the whole country, they had good professional skills in using the new working methods, personal penetration, and the right attitude and ability to enter into a discussion with sceptical colleagues. The technical school teacher, who had personal experience of the subjects from
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previous courses, did the selection. The course included training in the new working techniques, teaching skills, communication, educational training, and ergonomics. Course notes, with instructions about how to use the new working methods and descriptions of the different kind of tools, were issued to the supervisors. 2.2.2. ‘Pilot’ courses and courses for floor layers Four courses were arranged in October 2002, with a total of 38 floor layers as participants. The specialist teacher, with knowledge in using the new working methods, was used at these courses. The courses were used as pilots to investigate whether the courses had the right length and content. From February to June 2003, 43 courses were arranged with a total of 254 participants (approximately one third of the skilled floor layers in Denmark). The courses took place at local technical schools throughout Denmark. The 10 floor layers who had had the 2-week supervisor courses were used as teachers at the courses. The average number of participants at each course was 5.5 (3–13). The high participation rate was reached due to a considerable effort from the organisational unions, which made contacts with the employers and the local trade unions, with the aim of getting enough participants. The technical school in Viborg did the practical coordination. The programme for the courses were: theoretical instruction in the different kinds of new tools, theoretical instruction in the use of the tools, practical instruction in the use of the tools when priming, gluing, welding, cutting welding wire, and up-cutting linoleum. All participants were provided with a complete set of tools including a telescopic stick, intercostals fitting, and fitting for gluing, filling, and up-cutting. The set was provided to the floor layers free of charge, and they could keep it as their own
property after the course. The set of tool were paid by a fund provided by the trade union and the employers’ association. The aim was that provision of the tools would motivate floor layers to participate in the course, and to apply the new methods after completion of the course. The floor layers were paid for the hours when they participated in the training; this was funded by a government grant for the courses. 2.3. Questionnaire study—base line information about the participants During the 2-day courses, the floor layers filled out questionnaires. The questionnaire included questions about musculoskeletal health problems from the Nordic Health Questionnaire (Kuorinka et al., 1987), psychological conditions, and knowledge about the new working methods. 2.4. Evaluation 2.4.1. Three-months follow-up questionnaire A 3-month follow-up was carried out by sending out questionnaires. This questionnaire included questions about present musculoskeletal health problems, psychosomatic conditions, and experiences in relation to the new working methods. The floor layers that reported musculoskeletal complaints during the previous 12 months were asked to describe their musculoskeletal symptoms, comparing their symptoms before the courses with the symptoms at the time they answered the questionnaire on a ordinal categorical scale from 4 (much better) through 0 (the same) to +4 (much worse).
Table 2 Questionnaire study, interviews, quality study and time study
Questionnaire study of floor layers Interview
Study population (n)
Responders
First questionnaire
292
285 (98%)
Three-months follow-up
285
212 (74%)
Floor layers
2, who did not use the new tool before or after courses 3, who did not use the tools before, but did after the course 5 that used the new tools before and after the course 4 1 2 2
Employers Trade Union Employers’ association Specialist teachers Quality study
Three work places, 6 work tasks
Time study
Three work places , 6 floor layers (3 participants at the courses and 3 supervisors)
Description of the material for the studies.
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2.4.2. Interviews With the aim of improving knowledge of the background causes for the promotion or restriction of influence when choosing to use the new working methods, semi-structured interviews were carried out with 10 floor layers, seven supervisors, and four employers (who had floor layers as participants on the courses). The subjects who were chosen for the interviews were floor layers who had not used the new working methods before participating in the courses but had used it following the course, or floor layers who used the new working methods neither prior to nor after the course, or floor layers who used the new working methods both prior to and after the course. A focus-group interview was made on four of the supervisors. A focus group interview were also made which included two members from the trade union, two from the employers’ association and two from the technical school. 2.4.3. Quality study In three work places, a blinded quality evaluation was made on the tasks: filling in material, gluing, welding, cutting of welding wire, and intersection. The evaluations were made for floors made in the traditional way and by using the new working methods. Experienced persons, one from the employers’ association and one specialist teacher representing the floor layers made the analyses by using the normally accepted method for quality evaluation in Denmark ‘GULV-FAKTA’. The evaluations were blinded so the examiner did not know which technique had been used. The evaluation includes filling up the straightedge of the material, with no visible channels, and, in gluing, that the glue must show no lakes or visible channels, and the glue must not be visible in the finished material. The intersection must not show irregularities in the cutting. The welding wire should be firmly fixed to the linoleum or vinyl and it must not be burned; the welding wire should be cut in such a way that it is in the same plan as the linoleum and there must be no cuts in the linoleum. 2.4.4. Time study Three floor layers experienced in using the new working methods and three floor layers who participated in the educationally training in using new working methods were selected for the study. Three work places were selected. All participants had the same training and experience as floor layers. The time study was done for the work tasks: gluing, filling in material, welding, and cutting of welding wire. The same floor layer did the work from a standing position and by the traditional way. A technical school teacher did the time-measurements using a stop watch. 3. Results
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working-position. The primary questionnaire was answered by 285 floor layers (response rate 98%). All participants were men, which reflected the gender-distribution in the trade. The average age was 37 years (17–61) and they had been employed as floor layer on average for 15 years (1–43). Table 2 shows the study population, and questionnaire responders. The participants in the courses came from all over Denmark. The results showed that, prior to the course, 48% had tried to use the new tools during the previous 12 months, compared to 13% in 2000. The number who had used the tools varied greatly depending on the firm in which the floor layers were employed, and it also differed between regions in the country as shown in Table 3. The number with musculoskeletal complaints had decreased a little in the body regions of neck, wrists, and elbows compared to results from the earlier study in 2000 (Jensen and Kofoed, 2003) (results not shown). The frequency of musculoskeletal complaints during the last 12 months were higher among floor layers who reported using the new tools weekly before the courses (67%) compared to floor layers that have never used the tools (53%), have used them occasionally (48%) or daily (43%), as shown in Table 3 (difference not statistical significant p ¼ 0:54) (Results are only shown for the subjects who responded to the followup questionnaire, N ¼ 208). 3.2. Results from 3-months follow-up questionnaire study The 3-month follow-up questionnaires were answered by 212 floor layers (response rate 74%), as shown in Table 2. Four subjects had only answered a part of the questions and are deleted from the finally results. 3.2.1. Experiences with the new working methods Experiences with the se of the new working methods are shown in Table 3. The results are compared with the experiences before the courses. Following the courses, 86% have now used the new tools compared to 48% prior to the course. The increase is especially seen in the group using the tools weekly/daily (from 11% to 43%). The floor layers who reported to use the new working methods daily after the courses (n ¼ 22) had, before the courses, used the method daily (n ¼ 7), weekly (n ¼ 3), occasionally (n ¼ 7, and never (n ¼ 5). There are still differences in the proportion of floor layers using the new tools in different firms and between the different regions in the country. The new tools were mostly used for gluing and filling. The experiences with the new working methods before and after the courses are shown in Table 3. Sixty-eight percent of the participants reporting using the tools after the course found them easy to use, and 53% found that it made the job tasks go faster.
3.1. Results from the first questionnaire In total, 281 floor layers and 11 apprentices participated in the 47 courses about floor laying from an upright
3.2.2. Musculoskeletal complaints The frequency of musculoskeletal complaints were higher among floor layers using the new tools weekly after
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Table 3 Pre- and post-effects (before and after the courses). Results from the questionnairesa Before training (N ¼ 208) N (%)
Three months after training (N ¼ 208) N (%)
Used new working methods during the past 12 months Never Occasionally Weekly Daily
94 92 15 7
(45.2%) (44.2%) ( 7.2%) ( 3.4%)
23 95 68 22
(11.1%) (45.7%) (32.7%) (10.6%)
Used new working methods weekly/daily; by region: J Sealand, Bornholm J Jutland, Fyn, Lolland—Falster Experience with the tools: have not used the tools (total) Do not know the tools Not enough instruction Work-task too small Have not time for training Takes too long
5 16 94 39 48 19 4 9
( 6%) (13%) (45%) (41%) (51%) (20%) ( 4%) (10%)
27 61 23 0 1 16 0 0
(33%) (51%) (11%) ( 0%) ( 4%) (70%) ( 0%) ( 0%)
6 3 114 47 44 18 9 3
( 6%) ( 3%) (55%) (41%) (39%) (16%) ( 8%) ( 3%)
1 2 185 95 121 4 77 5
( 4%) ( 9%) (89%) (53%) (68%) ( 1%) (42%) ( 4%)
The tools are not developed enough Want to do as usual Have used the tools (total) Work goes faster Easy to use Not enough instruction Work task too small Want to do as usual Knee complaints during past 12 months: by use of new working methods Use of new working methods Before the course Never (n ¼ 91) Occasionally (n ¼ 86) Weekly (n ¼ 15) Daily (n ¼ 7)
Knee complaints during past 12 months: N (%) 48 (53%) 41 (48%) 10 (67%) 3 (43%)
Use of new working methods
Knee complaints during past 12 months: N (%) 47 (52%) 50 (58%) 11 (73%) 0 (0%) Knee complaints during past 12 months: n (%) 8 (40%) 49 (53%) 41 (61%) 9 (41%)
After the course Never (n ¼ 20) Occasionally (n ¼ 93) Weekly (n ¼ 67) Daily (n ¼ 22) Quality studyb
Traditional working method Small cavities when priming Some failures in cutting of welding wire
New working method Small cavities when priming Some failures in cutting of welding wire
Time studyc
Traditional working method
New working method
Floor layer Supervisor
39 min 33 s 35 min 41 s
40 min 20 s 35 min 21 s
a
Results only reported for the subjects who responded to the follow-up questionnaire (N ¼ 208). Quality study of different work-tasks in three workplaces and included the work tasks: gluing, welding, cutting welding wire, and intersection. Only failures are reported. c The results are shown as a sum from three workplaces; three experienced floor layers, and three floor layers participated in the courses and I included the work tasks: gluing, welding, cutting welding wire, and intersection. b
the courses (61%) compared to floor layers never using the tools (40%), use it occasionally (53%) or daily (41%), as shown in Table 3 (differences not statistically significant p ¼ 0:22). None of the floor layers who had never used the new working methods reported reduced knee pain after the courses vs. 8% of floor layers who have used it
occasionally, 24% who have used it weekly, and 41% who have used it daily (statistical significant, po0:0001). When comparing floor layers who had used the new tools weekly/daily with floor layers who had used the new tools never/occasionally, there was a higher frequency of floor layers who reported reduced musculoskeletal
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Table 4 Relationships between musculoskeletal complaints and use of new tools Use of new tools
Totalc
Musculoskeletal complaints No
Unchanged
Increased paina
Reduced painb
Use new tools Never/occasionally Weekly/daily Total
Neck 83 (75%) 58 (67%) 141 (72%)
24 (22%) 16 (18%) 40 (20%)
1 (1%) 2 (2%) 3 (2%)
2 (2%) 11 (13%) 13 (7%)
110 87 197
Use new tools Never/occasionally Weekly/daily Total
Shoulder 79 (70%) 58 (65%) 137 (68%)
27 (24%) 16 18%) 43 (21%)
4 (4%) 3 (3%) 7 (3%)
3 (3%) 12 (13%) 15 (7%)
113 89 202
Use new tools Never/occasionally Weekly/daily Total
Elbow 98 (85%) 75 (84%) 173 (84%)
16 (1%) 9 (10%) 25 (12%)
0 (0%) 2 (2%) 2 1%)
1 (1%) 3 (3%) 4 (2%)
115 89 204
Use new tools Never/occasionally Weekly/daily Total
Hand/wrist 77 (71%) 60 (67%) 137 (70%)
25 (23%) 13 (15%) 38 (19%)
0 (0%) 3 (3%) 3 (2%)
6 (6%) 13(15%) 19(10%)
108 89 197
Use new tools Never/occasionally Weekly/daily Total
Upper back 91 (81%) 70 (80%) 161(80%)
17 (9%) 10 (11%) 27 (14%)
3 (3%) 1 (1%) 4 (2%)
2 (2%) 7 (8%) 9 (4%)
113 88 201
Use new tools Never/occasionally Weekly/daily Total
Lower back 46 (43%) 37 (42%) 83 (42%)
50(46%) 36(40%) 86(44%)
6 (6%) 2 (2%) 8 (4%)
6 (6%) 14 (16%) 20 (10%)
108 89 197
Use new tools Never/occasionally Weekly/daily Total
Hip 100 (88%) 81 (90%) 181 (89%)
12 (11%) 8 (9%) 20 (10%)
1 (1%) 1 (1%) 2 (1%)
1 (1%) 0 (0%) 1 (0%)
114 90 204
Use new tools Never/occasionally Weekly/daily Total
Knee 56 (51%) 39 (43%) 95 (48%)
43 (39%) 23 (26%) 66 (33%)
4 (4%) 3 (3%) 7 (4%)
7 (6%) 25 (28%) 32 (16%)
110 90 200
Use new tools Never/occasionally Weekly/daily Total
Feet 98 (89%) 78 (88%) 176 (88%)
10 (9%) 8 9%) 18 (9%)
1 (1%) 1 (1%) 2 (1%)
1 (1%) 2 (2%) 3 (2%)
110 89 199
a
Increase pain: the number of answers going from +1 (worse) through +4 (much worse). Reduced pain: the number of answers going from 1 (better) through 4 (much better). c Total n ¼ 208 (missing not shown). b
complaints in neck (13% vs. 2%), shoulders (13% vs. 3%), hand/wrist (15% vs. 6%), low back (16% vs. 6%), and knees (28% vs. 6%). For elbows, upper back, hip, and feet, there were no differences between the groups. None of the musculoskeletal symptoms were increased when comparing the floor layers using the new and the traditional working methods. Results are shown in Table 4. 3.3. Results from 3-months follow-up interviews 3.3.1. Floor layers and supervisors Ten floor layers were interviewed, as shown in Table 5. All were positive in relation to the courses, and they
expected to use the new tools in the future. The floor layers who had not used the tools daily explained the reason as ‘work tasks too small’ or ‘being unemployed’. The floor layers who were the most sceptical before the course expected that the tools would not be adequate, that they would not be able to work as fast with the new tools as by the traditional methods, or that musculoskeletal complaints would move to other parts of the body, but only a few were negative after the course. The floor layers were very satisfied that they were provided with the sets of tools. In practice, the training sessions were optimal with ‘not more than 6 participants and in a room of not less than 30 square metres.’ The easiest was gluing and filling cracks,
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Table 5 Results from the interviews Experiences with the use of new tools Floor layers (n ¼ 10)
2 floor layers who have never used the new tools, either before or after the course Positive in relation to the new tools, but have not used it because the work task have been too small 3 floor layers who have not used the new tools before the course, but have used them after the course. Easy to use the new tool for filling and gluing, but they needed time to train to get familiar with it When getting familiar with the tools, there was a tendency for the work to go faster, especially for bigger work tasks. Positive for using them in the future 5 floor layers who have used the new tools before and after the courses Two floor layers used the new tools more after the course, one has used them a lot before and after the course, and two were unemployed after the course. All are very positive and wish to use the new tools, especially for bigger work tasks The courses were reported to be good, and the length satisfactory. They were very pleased that it was experienced floor layers who were training them: ‘The course was very good. All floor layers should be made to take that course.’ ‘It was a very good course. I was very surprised that it was so easy to use the new tools.’ ‘It was an incredibly good course, because of the way we were left to work with the tools, and because it was a floor layer who knew the trade who did the training.’
Experienced floor layers (supervisors) (n ¼ 5)
It was easy to train the floor layers. Nearly all participants were positive and interested. The floor layers found the tools easy to use, but training in organised courses is needed. Will use new tools themselves. Want to be used as teachers also on future courses
Employers (n ¼ 4)
All 4 employers were positive. They support the use of the new tools because they know the floor layers will have reduced musculoskeletal problems and they want to keep the floor layers at work, the courses had increased the number of floor layers using the new tools remarkably
Trade Union (n ¼ 1), Employers’ associations (n ¼ 2), and specialist teacher school (n ¼ 3)
Number of participants participated in courses using new tools: 1997–2000: 10; 2000–2001: 17; 2002–2003: 292, the courses were a great success because of the numbers of participants and the feed back from the floor layers. The process has been a success because: ‘The organizations had felt an obligation to do something. This is an example which shows that we can make changes if we join our forces’.
and the most difficult was welding from a standing position. Cutting of welding wire was a great success. All supervisors were surprised that the floor layers were so positive and that it was so easy to train them. The difficulties had been in organising the courses at the local technical schools, to find the appropriate responsible persons at the different schools, and to make some of the schools understand that it was necessary to have large and well-prepared rooms available. 3.3.2. Feedback for the trade union, employers’ association, and specialist technical school teachers The organizing group including members from the trade union and employers’ association (four individuals in total), the technical school teachers (two individuals), four supervisors, and the two authors, participated in a 2-day seminar in June 2003. The evaluation was presented as lectures from the participants, semi-structured group interviews, and a concluding open discussion. All found it very promising that as many as 292 floor layers had participated in the courses. This was more than one third of the total number of floor layers in the trade union in the whole of Denmark. By contrast, only 10 floor layers had participated in courses on floor laying from a standing position during the previous 4 years, 1997–2000, see Table 5. One of the reasons for success was reported as: ‘The organizations had felt an obligation to do something. This
is an example which shows that we can make changes if we join our forces’. The existence of sufficient and well-developed tools was mentioned as another reason for the success of the courses. The most important activities for the trade organisations have been the marketing of the courses, participation in the regional meetings, finding participants, and ensuring the funding. The employers’ association made contacts with the employers, arguing in favour of participation on the grounds that there would be a ‘fall in sick leave over time’, and because the tools would be provided free of charge. When they were contacted, most employers were supportive. It was the first time that the technical school had used supervisors. There had been a lot of worry about the issue: Are supervisors able to teach their colleagues following a 14-day course. They therefore tried to plan the courses for each of the supervisors as a series, so that they would not have to start afresh each time. The organizing group found that the use of supervisors had had a very positive effect on the process. 3.4. Time study and quality study The results from the time study and quality study are shown in Table 3. When calculating the work tasks as an average of all work task registered, the traditional and the new working method used nearly the same amount of time.
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At one work place, gluing was done faster in an upright working-position for both the floor layer and the supervisor, on the second it was done slower by both workers, and for the last work place it was faster for one and slower for the other floor layer. Priming and intersection was also done faster for some and slower for others. Welding was done faster with the new working method at all work places and by both floor layers and supervisors. When comparing the traditional and the new working methods the quality of none of the work tasks differed significantly. Nearly all tasks were with small cosmetic or insignificant failures. 4. Discussion The study showed an increased frequency of floor layers using the new working methods during the implementation. The new working methods reduced the degree of knee complaints comparing floor layers who did change their working methods with those who did not, and the use of the new working methods did not increase the complaints elsewhere. The quality of the work and the time used was the same using traditional and new working methods. The hypothesis of the study was therefore confirmed, except that the time taken using the new working methods did not show any decrease. It cannot be assumed that the success of the changed working methods will be sustained when the highly motivated experts and the unions are withdrawn from the intervention process. The study has to be evaluated within three months after the training because of a demand from one of the foundations. However, it would have been better to make an assessment of the outcome-variables repeatedly over a period of more than 1 year, to test these preliminary results, as suggested by Westgaard and Winkel (1997). 4.1. Evaluation of the process In earlier studies, it has proved difficult to induce employers and their employees to adopt new technologies (Ringen and Stafford, 1996; Schneider, 1995; van der Molen et al., 2005). Changes have been introduced successfully if the methods were found to be relevant from the workers’ point of view or if they were the result of regulations from the authorities (Ringen et al., 1995). The changes reported in this study succeeded as a result of a combination of several different factors. The main stimulus to the process had been repeated scientific reports about the harmful health effects on the musculoskeletal system which result from working in a kneeling position; these reports have been presented repeatedly to the trade organizations, the employers, the floor layers, the apprentices, and the technical school teachers. It can be assumed that a collective understanding has consequently been created about the general health problems which result from working in kneeling positions. Additionally, the trade has experienced increasing problems in its efforts to recruit
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new floor layers and has an increasing need to retain skilled floor layers in the trade. Successful implementation of change is more likely to be achieved when workers and their unions take the initiative, and consequently are self-motivated to make improvements. It was therefore considered to be important to establish a feeling of ownership of the project, to use local experts and to signal from the beginning of the project that there was an agreement in support of the project between the trade union and the employers’ association, the employers, and the employees. The positive findings in this study strengthen support for the power of participative ergonomics approaches which was found in other studies (De Jong et al., 2003; Haines et al., 2002; Westgaard and Winkel, 1997). In this study, the role of the trade organizations was considerable, and there was mutual agreement about the policy, strategy, and attitudes. This was the basis which enabled sufficient information about the project to be given to the floor layers and their employers, for the high participation rate at the regional meetings and at the courses, and for the funding for the provision of tools freeof-charge to the participants. The results from the study showed that, from 2000 till 2003, there was an increase from 13% to 48% in floor layers who had tried the new tools. The implementation had therefore been an ongoing process, and the time may therefore have been the ripe for a more substantial goaldirected effort. This study also indicates the importance of developing the right tools, which, as in this case, prove to be effective and easy to use. It also points to the value of experience with the tools, both theoretical and practical, becoming well established among the technical school teachers. These findings are also supported by other studies (Schneider, 1995; Robertson and O’Neill, 2003). Establishing the correct size and the best organisation of the courses, especially the selection and the use of the supervisors, may also have played a positive role. These initiatives were necessary if a large number of floor layers were to be trained in a short time. It is also seen as positive that it was fellow-floor-layers, who were recognised as knowing the trade as insiders, who did the training and acted as role models. It is possible that the central role of the supervisors has promoted the feeling of ownership of the project. The local champions have in this way played a more active role, and had more individual responsibility than is typically found in intervention studies. It was also of great importance that the floor layers could keep the tools as their own property after the courses. This may have prevented the problems which could have arisen if the floor layers had experienced difficulties in obtaining the tools, and it meant that the floor layers were able to use the new working methods immediately after the courses, if their ongoing work included relevant tasks. This has been confirmed in this project.
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A positive climate for the intervention process and the results may in this study be provided by favourable combinations of different factors in the trade, such as good collaboration between the researchers, trade unions and training organizations, development of new tools which were accepted by the employees, provision of the tools free of charge, the ‘train the trainer’ approach, the mutuality of interests and policies amongst employers and the employees and their unions, and widening support for health and safety initiatives. To ensure that the process continues within the floor lying trade, it will be important to follow-up with further initiatives. The trade organizations have already decided that, in the future, apprentices should be provided with the new tools in their toolboxes, and the training courses are now obligate for apprentice floor layers. It will also be necessary to provide more courses, to follow-up the courses which have already been completed, and to arrange new courses for floor layers who have not yet participated. 4.2. Evaluation of the effects 4.2.1. Experience with the new working methods There was an increase in the use of the new tools from 13% in 2000, to 48% before the courses and 86% after the courses. The frequency of floor layers using the new tools weekly/daily especially increased (from 11% to 43%) after the courses. This indicates that the courses had a very substantial effect on the frequency of using the tools. This study indicates that ergonomic intervention can diminish exposure to kneeling work tasks. In an earlier study, we found that knee-straining work tasks in the floor layers’ trade constitutes 56% of the work time (Jensen et al., 2000a, b). It is possible to carry out a large part of the work tasks from an upright position by using the new working methods. In the interviews, the floor layers reported that 50–60% of these work tasks can now be carried out from an upright position. By taking these reports into account, the use of the new working methods can reduce the total amount of knee-straining activity from 60% to approximately 30%. This level corresponds to the amount of knee-straining work activity for carpenters (Jensen et al., 2000a; Holmstro¨m et al., 1995) or plumbers and pipe fitters (Eenberg et al., 2002). Prior to this study, the floor layers were concerned about not having time for training new working methods. They were also concerned about the risk of reducing the quality of their work. The time study showed that the time used for a particular task was at least as fast when using the new methods as when using the traditional working method. More than half of the floor layers participating in the questionnaire study even reported the new methods to be faster, especially when priming. The quality of the work showed no significant differences when comparing the new and the traditional methods. These results suggest (bearing in mind that the observation time was short) that the new working methods in higher degree were used after training, did not
decrease the quality of work and were as fast as the traditional work methods. 4.2.2. Improvement of the musculoskeletal complaints Prior to the courses, the floor layers had been concerned about the possibility of getting more pain in their elbows and shoulders when using the new tools. Many floor layers with musculoskeletal complaints reported reduction in complaints, including neck, shoulders, wrists, and knees after the courses. However, bearing in mind the short observation time in this study, the results may indicate that the new working methods do not produce new health problems in other parts of the musculoskeletal system. Long-term effects on the musculoskeletal system cannot be determined from our present results. A follow-up study after 1–2 years is necessary to look at longer-term effects. To document a hoped-for decrease in the prevalence of knee osteoarthritis, the follow-up period may need to be even longer, probably several or even many years. Floor layers, who used the new working methods weekly or daily, had a reduction of knee pain compared to floor layers using the new working methods occasionally or never. However, it is possible that the group which changed its working methods was more satisfied, and consequently reported better outcomes, such as less musculoskeletal pain, than the group which did not use the new methods. The reduction showed a dose–response relationship which supports the suggestion that there may be a real relationship. Reports of less pain in the musculoskeletal system by the floor layers using the new tools were only evident for the complaints of pain in neck, shoulder, wrist and the knees and not from the rest of the body (elbows, upper and low back, hips, and feet), and this contradicts this argument. The outcome sustainability might be assessed by repeated observations after a period of more than 1 year, and it would be relevant at that time to include a control group which has not participated in the first part of the study when comparing the musculoskeletal complaints as suggested by Westgaard and Winkel (1997). These results indicate (bearing in mind that the observation time was short) that the new working methods may reduce the musculoskeletal complaints and that they do not produce new health problems. 5. Conclusion An implementation of new working methods in the floor layer trade succeeded when floor layers were trained in new working methods by the trainer approach combined with information and facilitation. A 3 months evaluation showed a reduction in knee complaints comparing floor layers who did change their working methods with those who did not. The use of the new working methods did not result in musculoskeletal problems in elbows, wrists, upper or low back or in other parts of the musculoskeletal system. The new working methods were as productive as the
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traditional methods and the quality of work were the same as a result of using the new working methods. Acknowledgements The study was supported by the European Agency for Safety and Health at Work and by the Foundation of Employers and Trade Union for Wood and Construction. References De Jong, A., Vink, P., 2002. Participatory ergonomics applied in installation work. Appl. Ergon. 33, 439–448. De Jong, A., Vink, P., De Kroon, J., 2003. Reasons for adopting technological innovations reducing physical workload in bricklaying. Ergonomics 46, 1091–1108. Eenberg, W., Nielsen, J., Mikkelsen, K.L., Bach, E., Villadsen, E., 2002. Arbejdsrelateret knæbesvær, psykosocialt arbejdsmiljø, arbejdsevne og afgangsa˚rsager blandt blik- og rørarbejdere [Work-related Kneetroubles, Psychosocial Work Environment, Work Capacity and Causes of Retirement Among Plumbers and Pipelayers]. Arbejdsmiljøinstituttet, Copenhagen. Denmark, pp. 1–109. Ekstro¨m, H., Engholm, G., Nyqvist, B., Wallenquist, A., 1983. Kna¨besva¨r som arbetsmedicinskt problem (Knee Disorders as an Occupational Problem). Byggha¨lsans Forskningsstiftelse, Stockholm. Haines, H., Wilson, J., Vink, P., Koningsveld, E., 2002. Validating a framework for participatory ergonomics. Ergonomics 45, 309–327. Holmstro¨m, E., Mortiz, U., Engholm, G., 1995. Musculoskeletal disorders in construction workers. Occup. Med. 10, 295–312. Jensen, L., Kofoed, L., 2003. Musculoskeletal disorders among floor layers: is prevention possible? Appl. Occup. Environ. Hyg. 17, 797–806. Jensen, L., Eenberg, W., Mikkelsen, S., 2000a. Validity of self-reporting and video-recording for measuring knee-straining work postures. Ergonomics 43, 310–316. Jensen, L., Mikkelsen, S., Loft, I., Eenberg, W., 2000b. Work-related knee disorders in floor layers and carpenters. JOEM 42, 835–842. Jensen, L., Mikkelsen, S., Loft, I., Eenberg, W., Bergmann, I., Løgager, V., 2000c. Radiographic knee osteoarthritis in floorlayers and carpenters. Scand. J. Work Environ. Health 26, 257–262. Kivima¨ki, J., Riihima¨ki, H., Ha¨nninen, K., 1992. Knee disorders in carpet and floor layers and painters. Scand. J. Work Environ. Health 18, 310–316.
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Kuorinka, I., Jonsson, B., Kilbom, A., Vinterberg, H., Biering-Sørensen, F., Andersson, G., Jørgensen, K., 1987. Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms. Appl. Ergon. 18, 233–237. Moore, J.S., Garg, A., 1996. Use of participatory ergonomics teams to address musculoskeletal hazards in the red meat packing industry. Am. J. Ind. Med. 29, 408. Moore, J.S., Garg, A., 1997. Participatory ergonomics in a red meat packing plant part II: case studies. Am. Ind. Hyg. Assoc. J. 58, 498–508. Ringen, K., Stafford, E.J., 1996. Intervention research in occupational safety and health: examples from construction. Am. J. Ind. Med. 29, 314–320. Ringen, K., Seegal, J., Englund, A., 1995. Safety and health in the construction industry. Annu. Rev. Public Health 16, 165–188. Robertson, M.M., O’Neill, M.J., 2003. Reducing musculoskeletal discomfort: effects of an office ergonomics workplace and training intervention. Int. J.Occup. Safety 9, 491–502. Schneider, F., 2001. Four steps to an effective office ergonomics program. Ergon. Suppl., 140–144. Schneider, S., 1995. Ergonomics. Implement ergonomic. Interventions in construction. Appl. Occup. Environ. Hyg. 10, 822–824. Thun, M., Tanaka, S., Smith, A.B., Halperin, W.E., Lee, S.T., Luggen, M.E., Hess, E.V., 1987. Morbidity from repetitive knee trauma in carpet and floor layers. Br J. Ind.Med. 44, 611–620. van der Molen, H., 2005. Evidence-based implementation of ergonomic measures in construction work. Thesis. Coronal Institute of Occupational and Environmental Health, Research Institute Am COGG. Arbouw, the National Occupational Health and Safety Institute in the Dutch Construction Industry, Amsterdam, the Netherlands, pp. 1–209. van der Molen, H.F., Sluiter, J.K., Hulshof, C.T., Vink, P., van Duivenbooden, C., Holman, R., Frings-Dresen, M.H., 2005. Implementation of participatory ergonomics intervention in construction companies. Scand. J. Work Environ. Health 31, 191–204. Vink, P., Lourijsen, E., Wortel, E., Dul, J., 1992. Experiences in participatory ergonomics: results of a roundtable session during the 11th IEA Congress, Paris, July 1991. Ergonomics 35, 123–127. Westgaard, R.H., Winkel, J., 1997. Ergonomic intervention research for improved musculoskeletal health: a critical review. Int. J. Ind. Ergon. 20, 463–500.
Applied Ergonomics 38 (2007) 655–665 www.elsevier.com/locate/apergo
Effects of training to implement new tools and working methods to reduce knee load in floor layers Lilli Kirkeskov Jensen, Claus Friche Department of Occupational Medicine, Sygehus Viborg, Resenvej 25, DK 7800 Skive, Denmark Received 15 December 2004; accepted 6 March 2006
Abstract The purpose was to measure the effect of a participatory ergonomics implementation strategy consisting of information, education, and facilitation on the use of new tools and working methods in the floor laying trade. Floor layers (n ¼ 292) were trained in using new working methods. The effects were evaluated by using questionnaires, interviews, and assessments of quality and productivity. Following the training, 43% had used the new working methods weekly/daily compared to 11% before. There was a reduction in the degree of selfreported pain in the knees among the floor layers using the new working methods weekly or daily compared to those using them never or occasionally. The musculoskeletal complaints did not increase from any other region and the quality and the productivity of the work were not decreased. This indicates that within a 3-months perspective the implementation strategy succeeded. r 2006 Elsevier Ltd. All rights reserved. Keywords: Implementation; New working methods; Construction industry
1. Introduction In Denmark, 900 floor layers are members of the trade union, and 120 firms are members of the employers’ association, which covers about 90% of all floor layers in Denmark. Floor- and carpet layers (hereafter referred to collectively as floor layers) install linoleum, carpet, and vinyl floorings. Their work tasks include removal of old flooring, grinding, filling, installation of underlay, measuring and cutting materials, gluing, welding, installation of plastic skirting board, and transport. Earlier studies have shown that the floor layers spend more than half of their working day in knee-straining working positions (kneeling or squatting) (Ekstro¨m et al., 1983; Jensen et al., 2000b; Kivima¨ki et al., 1992; Thun et al., 1987). In earlier studies, floor layers were found to have an increased frequency of knee complaints and knee osteoarthritis compared to other trades in the construction industry (Holmstro¨m et al., 1995;
Corresponding author. Tel.: +45 89 27 48 50; fax: +45 89 27 48 79.
E-mail address: [email protected] (L.K. Jensen). 0003-6870/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.apergo.2006.03.008
Jensen et al., 2000b, c; Kivima¨ki et al., 1992; Thun et al., 1987). In Denmark since 1996, the trade union and the employers’ association have, through campaigns and regional meetings, tried to change the attitude of the trade and to make the workers supportive towards standing up when they work. During recent years, new tools have been introduced which make it possible to carry out some of the job tasks (such as gluing, filling, welding, up-cutting, and cutting of welding wire) from a standing working-position. Floor layers and teachers at the technical school for floor layers have tested the tools. The system is based on a telescopic stick, an intercostals fitting, and special fittings for these specific job tasks (gluing, filling, welding, and upcutting). The traditional and new working methods are illustrated in Fig. 1. However, in spite of such campaigns, and the development of the new tools, an investigation from 2000 found that only 13% of the floor layers had used the new working methods during the previous 12 months (Jensen and Kofoed, 2003). The floor layers reported that the reason for the lack of change was that the new methods needed to be learned, and that it was difficult to find time during a
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Fig. 1. (a) Floor layers. Gluing: working traditionally (left), and using new (right) working methods. (b) Floor layers. Filling: working traditionally (left), and using new (right) working methods.
busy working day to try new methods. They also reported that educational training was necessary. The floor layers in general were very sceptical, especially about taking advice from academics, and would only take suggestions or criticism from people who were experienced in their trade. They also reported that the tools were not satisfactory in use (Jensen and Kofoed, 2003). The 2000 study showed that implementation of new working-methods was very difficult, and this agreed with the findings of other studies (De Jong and Vink, 2002; Schneider, 2001; van der Molen, 2005). Schneider (2001) described four key factors in establishing an effective ergonomics programme: (i) strong management support, (ii) efficient assessment, (iii) effective training, and (iv) improvements to the physical work environment. The overall goal of this study has been to change the behaviour of floor layers, and thereby to implement the new working methods in the floor laying trade. Compared with the earlier study in 2000 (Jensen and Kofoed, 2003)the tools were much more developed, and there was more support from the employers and employees and their
organisations, since the project had funding to give one third of the floor layers in Denmark the tools and courses free of charge. Many researchers suggest a participatory approach to the development and implementation of new working methods and new tools to reduce physical demands at work (Haines et al., 2002; Moore and Garg, 1996, 1997; van der Molen, 2005; van der Molen et al., 2005; Vink et al., 1992). There is no single unifying model of participatory ergonomics, and an adjusted model has been constructed for this study. In earlier studies, seven levels have been described in the changing of behaviour in relation to an implementation strategy: (1) awareness of the physical work demands and health risks associated with the use/no use of ergonomic measures, (2) understanding of the ergonomic measures, (3) desire to provide or use the ergonomic measures, (4) intention to buy, hire or use the ergonomic measure, (5) ability to use the ergonomic measures, (6) gaining experience by using the ergonomic measure, and (7) continuing use of the ergonomic measures (van der Molen
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et al., 2005). In relation to these phases, the aim of the present study has been (1) to inform the workers and their employers about the new tools (where to buy, and how to use them) (2) to inform the workers about the tools and the health risk, comparing the conventional and the new working methods (3a) to show the new working methods to the floor layers, (3b) and thereby to convince the floor layers to use them, (4) to give the floor layers the tools (free of charge if they participated in a 2-day course, (5) to train them through a 2-days course in using the tools, (6) providing experience of using the new tools and methods during the training of the floor layers, (7) enabling them to continue using the new working methods after the courses. The main objective of this study is to investigate whether the implementation strategy has an effect on the use of the new working methods, and on the musculoskeletal complaints which occur, compared with using the conventional working methods. This objective was transferred into the following research questions: (1) Does the implementation strategy increase the frequency of floor layers using the new working methods? (2) Do the use of the new working methods reduce musculoskeletal complaints comparing floor layers who did change their working methods with those who did not. (3) Do the use of the new working methods results in more different health problems (e.g. musculoskeletal complaints from other regions)? (4) Are the new working methods as fast (i.e. as productive) as the traditional methods? (5) Is the quality of the work better, worse or the same as a result of using the new working methods? The hypothesis is that the implementation strategy would increase the use of the new working methods and thereby reduce the knee complaints among the floor layers and make the works go faster without reducing the quality of the work. 2. Material and methods In this study the participatory approach included the following phases: information-dissemination, policy making by trade union and employers’ association, information of employers and employees about the policy, the new working methods and the health risk, training of supervisors, training of floor layers, and evaluation, as shown in Table 1. 2.1. Information process In the Autumn of 2002, eight regional 2-h meetings were arranged by the trade union, the employers’ association, and a specialist teacher from the technical school in Viborg (which is the central technical school for floor layers in Denmark). The number of participants was 174 (91% floor layers and 9% employers). At the meetings, the new working methods were introduced in theory and in practise. An extensive and goal-directed written and oral presentation, including possibilities to become acquainted
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Table 1 The phases in the participatory ergonomics implementation strategy: from research to changing work-methods in the floor laying trade Information provided about health risks, based on relevant research Development of usable and acceptable tools Local meetings for 174 floor layers and their employers to provide information about: Health risks How to use the tolls Support (policy) from trade union and employers’ association Training by a specialist teacher Four 2-days courses for 38 floor layers (pilots) Training of supervisors Two-week course for expert floor layers (supervisors)
1996–2002 2000–2002 Autumn 2002
January 2003
Training of floor layers by supervisors at local technical schools around the country Two-day courses for 254 floor layers Provision of tools (free of charge) to the participants
February–June 2003
Base-line- study: First Questionnaire
February–June 2003
Evaluation: Second questionnaire Interviews Quality study Time-study
June–September 2003 June–September 2003 August–September 2003 August-September 2003
with the new working methods and tools, was made and distributed. Representatives of the employers’ association and the trade union at this meeting stated that they concurred in supporting the process, and wished the new working methods to be used. 2.2. Education of teachers and floor layers 2.2.1. Course for supervisors The training of the floor layers who would subsequently be used as teachers (hereafter referred to as ‘supervisors’) was considered necessary if the new working methods were to be communicated to, and accepted by, a large proportion of the floor layers. A total of 10 floor layers participated in a 2-week course in January 2003. They were chosen on the following criteria: they geographically represented the whole country, they had good professional skills in using the new working methods, personal penetration, and the right attitude and ability to enter into a discussion with sceptical colleagues. The technical school teacher, who had personal experience of the subjects from
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previous courses, did the selection. The course included training in the new working techniques, teaching skills, communication, educational training, and ergonomics. Course notes, with instructions about how to use the new working methods and descriptions of the different kind of tools, were issued to the supervisors. 2.2.2. ‘Pilot’ courses and courses for floor layers Four courses were arranged in October 2002, with a total of 38 floor layers as participants. The specialist teacher, with knowledge in using the new working methods, was used at these courses. The courses were used as pilots to investigate whether the courses had the right length and content. From February to June 2003, 43 courses were arranged with a total of 254 participants (approximately one third of the skilled floor layers in Denmark). The courses took place at local technical schools throughout Denmark. The 10 floor layers who had had the 2-week supervisor courses were used as teachers at the courses. The average number of participants at each course was 5.5 (3–13). The high participation rate was reached due to a considerable effort from the organisational unions, which made contacts with the employers and the local trade unions, with the aim of getting enough participants. The technical school in Viborg did the practical coordination. The programme for the courses were: theoretical instruction in the different kinds of new tools, theoretical instruction in the use of the tools, practical instruction in the use of the tools when priming, gluing, welding, cutting welding wire, and up-cutting linoleum. All participants were provided with a complete set of tools including a telescopic stick, intercostals fitting, and fitting for gluing, filling, and up-cutting. The set was provided to the floor layers free of charge, and they could keep it as their own
property after the course. The set of tool were paid by a fund provided by the trade union and the employers’ association. The aim was that provision of the tools would motivate floor layers to participate in the course, and to apply the new methods after completion of the course. The floor layers were paid for the hours when they participated in the training; this was funded by a government grant for the courses. 2.3. Questionnaire study—base line information about the participants During the 2-day courses, the floor layers filled out questionnaires. The questionnaire included questions about musculoskeletal health problems from the Nordic Health Questionnaire (Kuorinka et al., 1987), psychological conditions, and knowledge about the new working methods. 2.4. Evaluation 2.4.1. Three-months follow-up questionnaire A 3-month follow-up was carried out by sending out questionnaires. This questionnaire included questions about present musculoskeletal health problems, psychosomatic conditions, and experiences in relation to the new working methods. The floor layers that reported musculoskeletal complaints during the previous 12 months were asked to describe their musculoskeletal symptoms, comparing their symptoms before the courses with the symptoms at the time they answered the questionnaire on a ordinal categorical scale from 4 (much better) through 0 (the same) to +4 (much worse).
Table 2 Questionnaire study, interviews, quality study and time study
Questionnaire study of floor layers Interview
Study population (n)
Responders
First questionnaire
292
285 (98%)
Three-months follow-up
285
212 (74%)
Floor layers
2, who did not use the new tool before or after courses 3, who did not use the tools before, but did after the course 5 that used the new tools before and after the course 4 1 2 2
Employers Trade Union Employers’ association Specialist teachers Quality study
Three work places, 6 work tasks
Time study
Three work places , 6 floor layers (3 participants at the courses and 3 supervisors)
Description of the material for the studies.
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2.4.2. Interviews With the aim of improving knowledge of the background causes for the promotion or restriction of influence when choosing to use the new working methods, semi-structured interviews were carried out with 10 floor layers, seven supervisors, and four employers (who had floor layers as participants on the courses). The subjects who were chosen for the interviews were floor layers who had not used the new working methods before participating in the courses but had used it following the course, or floor layers who used the new working methods neither prior to nor after the course, or floor layers who used the new working methods both prior to and after the course. A focus-group interview was made on four of the supervisors. A focus group interview were also made which included two members from the trade union, two from the employers’ association and two from the technical school. 2.4.3. Quality study In three work places, a blinded quality evaluation was made on the tasks: filling in material, gluing, welding, cutting of welding wire, and intersection. The evaluations were made for floors made in the traditional way and by using the new working methods. Experienced persons, one from the employers’ association and one specialist teacher representing the floor layers made the analyses by using the normally accepted method for quality evaluation in Denmark ‘GULV-FAKTA’. The evaluations were blinded so the examiner did not know which technique had been used. The evaluation includes filling up the straightedge of the material, with no visible channels, and, in gluing, that the glue must show no lakes or visible channels, and the glue must not be visible in the finished material. The intersection must not show irregularities in the cutting. The welding wire should be firmly fixed to the linoleum or vinyl and it must not be burned; the welding wire should be cut in such a way that it is in the same plan as the linoleum and there must be no cuts in the linoleum. 2.4.4. Time study Three floor layers experienced in using the new working methods and three floor layers who participated in the educationally training in using new working methods were selected for the study. Three work places were selected. All participants had the same training and experience as floor layers. The time study was done for the work tasks: gluing, filling in material, welding, and cutting of welding wire. The same floor layer did the work from a standing position and by the traditional way. A technical school teacher did the time-measurements using a stop watch. 3. Results
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working-position. The primary questionnaire was answered by 285 floor layers (response rate 98%). All participants were men, which reflected the gender-distribution in the trade. The average age was 37 years (17–61) and they had been employed as floor layer on average for 15 years (1–43). Table 2 shows the study population, and questionnaire responders. The participants in the courses came from all over Denmark. The results showed that, prior to the course, 48% had tried to use the new tools during the previous 12 months, compared to 13% in 2000. The number who had used the tools varied greatly depending on the firm in which the floor layers were employed, and it also differed between regions in the country as shown in Table 3. The number with musculoskeletal complaints had decreased a little in the body regions of neck, wrists, and elbows compared to results from the earlier study in 2000 (Jensen and Kofoed, 2003) (results not shown). The frequency of musculoskeletal complaints during the last 12 months were higher among floor layers who reported using the new tools weekly before the courses (67%) compared to floor layers that have never used the tools (53%), have used them occasionally (48%) or daily (43%), as shown in Table 3 (difference not statistical significant p ¼ 0:54) (Results are only shown for the subjects who responded to the followup questionnaire, N ¼ 208). 3.2. Results from 3-months follow-up questionnaire study The 3-month follow-up questionnaires were answered by 212 floor layers (response rate 74%), as shown in Table 2. Four subjects had only answered a part of the questions and are deleted from the finally results. 3.2.1. Experiences with the new working methods Experiences with the se of the new working methods are shown in Table 3. The results are compared with the experiences before the courses. Following the courses, 86% have now used the new tools compared to 48% prior to the course. The increase is especially seen in the group using the tools weekly/daily (from 11% to 43%). The floor layers who reported to use the new working methods daily after the courses (n ¼ 22) had, before the courses, used the method daily (n ¼ 7), weekly (n ¼ 3), occasionally (n ¼ 7, and never (n ¼ 5). There are still differences in the proportion of floor layers using the new tools in different firms and between the different regions in the country. The new tools were mostly used for gluing and filling. The experiences with the new working methods before and after the courses are shown in Table 3. Sixty-eight percent of the participants reporting using the tools after the course found them easy to use, and 53% found that it made the job tasks go faster.
3.1. Results from the first questionnaire In total, 281 floor layers and 11 apprentices participated in the 47 courses about floor laying from an upright
3.2.2. Musculoskeletal complaints The frequency of musculoskeletal complaints were higher among floor layers using the new tools weekly after
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Table 3 Pre- and post-effects (before and after the courses). Results from the questionnairesa Before training (N ¼ 208) N (%)
Three months after training (N ¼ 208) N (%)
Used new working methods during the past 12 months Never Occasionally Weekly Daily
94 92 15 7
(45.2%) (44.2%) ( 7.2%) ( 3.4%)
23 95 68 22
(11.1%) (45.7%) (32.7%) (10.6%)
Used new working methods weekly/daily; by region: J Sealand, Bornholm J Jutland, Fyn, Lolland—Falster Experience with the tools: have not used the tools (total) Do not know the tools Not enough instruction Work-task too small Have not time for training Takes too long
5 16 94 39 48 19 4 9
( 6%) (13%) (45%) (41%) (51%) (20%) ( 4%) (10%)
27 61 23 0 1 16 0 0
(33%) (51%) (11%) ( 0%) ( 4%) (70%) ( 0%) ( 0%)
6 3 114 47 44 18 9 3
( 6%) ( 3%) (55%) (41%) (39%) (16%) ( 8%) ( 3%)
1 2 185 95 121 4 77 5
( 4%) ( 9%) (89%) (53%) (68%) ( 1%) (42%) ( 4%)
The tools are not developed enough Want to do as usual Have used the tools (total) Work goes faster Easy to use Not enough instruction Work task too small Want to do as usual Knee complaints during past 12 months: by use of new working methods Use of new working methods Before the course Never (n ¼ 91) Occasionally (n ¼ 86) Weekly (n ¼ 15) Daily (n ¼ 7)
Knee complaints during past 12 months: N (%) 48 (53%) 41 (48%) 10 (67%) 3 (43%)
Use of new working methods
Knee complaints during past 12 months: N (%) 47 (52%) 50 (58%) 11 (73%) 0 (0%) Knee complaints during past 12 months: n (%) 8 (40%) 49 (53%) 41 (61%) 9 (41%)
After the course Never (n ¼ 20) Occasionally (n ¼ 93) Weekly (n ¼ 67) Daily (n ¼ 22) Quality studyb
Traditional working method Small cavities when priming Some failures in cutting of welding wire
New working method Small cavities when priming Some failures in cutting of welding wire
Time studyc
Traditional working method
New working method
Floor layer Supervisor
39 min 33 s 35 min 41 s
40 min 20 s 35 min 21 s
a
Results only reported for the subjects who responded to the follow-up questionnaire (N ¼ 208). Quality study of different work-tasks in three workplaces and included the work tasks: gluing, welding, cutting welding wire, and intersection. Only failures are reported. c The results are shown as a sum from three workplaces; three experienced floor layers, and three floor layers participated in the courses and I included the work tasks: gluing, welding, cutting welding wire, and intersection. b
the courses (61%) compared to floor layers never using the tools (40%), use it occasionally (53%) or daily (41%), as shown in Table 3 (differences not statistically significant p ¼ 0:22). None of the floor layers who had never used the new working methods reported reduced knee pain after the courses vs. 8% of floor layers who have used it
occasionally, 24% who have used it weekly, and 41% who have used it daily (statistical significant, po0:0001). When comparing floor layers who had used the new tools weekly/daily with floor layers who had used the new tools never/occasionally, there was a higher frequency of floor layers who reported reduced musculoskeletal
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Table 4 Relationships between musculoskeletal complaints and use of new tools Use of new tools
Totalc
Musculoskeletal complaints No
Unchanged
Increased paina
Reduced painb
Use new tools Never/occasionally Weekly/daily Total
Neck 83 (75%) 58 (67%) 141 (72%)
24 (22%) 16 (18%) 40 (20%)
1 (1%) 2 (2%) 3 (2%)
2 (2%) 11 (13%) 13 (7%)
110 87 197
Use new tools Never/occasionally Weekly/daily Total
Shoulder 79 (70%) 58 (65%) 137 (68%)
27 (24%) 16 18%) 43 (21%)
4 (4%) 3 (3%) 7 (3%)
3 (3%) 12 (13%) 15 (7%)
113 89 202
Use new tools Never/occasionally Weekly/daily Total
Elbow 98 (85%) 75 (84%) 173 (84%)
16 (1%) 9 (10%) 25 (12%)
0 (0%) 2 (2%) 2 1%)
1 (1%) 3 (3%) 4 (2%)
115 89 204
Use new tools Never/occasionally Weekly/daily Total
Hand/wrist 77 (71%) 60 (67%) 137 (70%)
25 (23%) 13 (15%) 38 (19%)
0 (0%) 3 (3%) 3 (2%)
6 (6%) 13(15%) 19(10%)
108 89 197
Use new tools Never/occasionally Weekly/daily Total
Upper back 91 (81%) 70 (80%) 161(80%)
17 (9%) 10 (11%) 27 (14%)
3 (3%) 1 (1%) 4 (2%)
2 (2%) 7 (8%) 9 (4%)
113 88 201
Use new tools Never/occasionally Weekly/daily Total
Lower back 46 (43%) 37 (42%) 83 (42%)
50(46%) 36(40%) 86(44%)
6 (6%) 2 (2%) 8 (4%)
6 (6%) 14 (16%) 20 (10%)
108 89 197
Use new tools Never/occasionally Weekly/daily Total
Hip 100 (88%) 81 (90%) 181 (89%)
12 (11%) 8 (9%) 20 (10%)
1 (1%) 1 (1%) 2 (1%)
1 (1%) 0 (0%) 1 (0%)
114 90 204
Use new tools Never/occasionally Weekly/daily Total
Knee 56 (51%) 39 (43%) 95 (48%)
43 (39%) 23 (26%) 66 (33%)
4 (4%) 3 (3%) 7 (4%)
7 (6%) 25 (28%) 32 (16%)
110 90 200
Use new tools Never/occasionally Weekly/daily Total
Feet 98 (89%) 78 (88%) 176 (88%)
10 (9%) 8 9%) 18 (9%)
1 (1%) 1 (1%) 2 (1%)
1 (1%) 2 (2%) 3 (2%)
110 89 199
a
Increase pain: the number of answers going from +1 (worse) through +4 (much worse). Reduced pain: the number of answers going from 1 (better) through 4 (much better). c Total n ¼ 208 (missing not shown). b
complaints in neck (13% vs. 2%), shoulders (13% vs. 3%), hand/wrist (15% vs. 6%), low back (16% vs. 6%), and knees (28% vs. 6%). For elbows, upper back, hip, and feet, there were no differences between the groups. None of the musculoskeletal symptoms were increased when comparing the floor layers using the new and the traditional working methods. Results are shown in Table 4. 3.3. Results from 3-months follow-up interviews 3.3.1. Floor layers and supervisors Ten floor layers were interviewed, as shown in Table 5. All were positive in relation to the courses, and they
expected to use the new tools in the future. The floor layers who had not used the tools daily explained the reason as ‘work tasks too small’ or ‘being unemployed’. The floor layers who were the most sceptical before the course expected that the tools would not be adequate, that they would not be able to work as fast with the new tools as by the traditional methods, or that musculoskeletal complaints would move to other parts of the body, but only a few were negative after the course. The floor layers were very satisfied that they were provided with the sets of tools. In practice, the training sessions were optimal with ‘not more than 6 participants and in a room of not less than 30 square metres.’ The easiest was gluing and filling cracks,
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Table 5 Results from the interviews Experiences with the use of new tools Floor layers (n ¼ 10)
2 floor layers who have never used the new tools, either before or after the course Positive in relation to the new tools, but have not used it because the work task have been too small 3 floor layers who have not used the new tools before the course, but have used them after the course. Easy to use the new tool for filling and gluing, but they needed time to train to get familiar with it When getting familiar with the tools, there was a tendency for the work to go faster, especially for bigger work tasks. Positive for using them in the future 5 floor layers who have used the new tools before and after the courses Two floor layers used the new tools more after the course, one has used them a lot before and after the course, and two were unemployed after the course. All are very positive and wish to use the new tools, especially for bigger work tasks The courses were reported to be good, and the length satisfactory. They were very pleased that it was experienced floor layers who were training them: ‘The course was very good. All floor layers should be made to take that course.’ ‘It was a very good course. I was very surprised that it was so easy to use the new tools.’ ‘It was an incredibly good course, because of the way we were left to work with the tools, and because it was a floor layer who knew the trade who did the training.’
Experienced floor layers (supervisors) (n ¼ 5)
It was easy to train the floor layers. Nearly all participants were positive and interested. The floor layers found the tools easy to use, but training in organised courses is needed. Will use new tools themselves. Want to be used as teachers also on future courses
Employers (n ¼ 4)
All 4 employers were positive. They support the use of the new tools because they know the floor layers will have reduced musculoskeletal problems and they want to keep the floor layers at work, the courses had increased the number of floor layers using the new tools remarkably
Trade Union (n ¼ 1), Employers’ associations (n ¼ 2), and specialist teacher school (n ¼ 3)
Number of participants participated in courses using new tools: 1997–2000: 10; 2000–2001: 17; 2002–2003: 292, the courses were a great success because of the numbers of participants and the feed back from the floor layers. The process has been a success because: ‘The organizations had felt an obligation to do something. This is an example which shows that we can make changes if we join our forces’.
and the most difficult was welding from a standing position. Cutting of welding wire was a great success. All supervisors were surprised that the floor layers were so positive and that it was so easy to train them. The difficulties had been in organising the courses at the local technical schools, to find the appropriate responsible persons at the different schools, and to make some of the schools understand that it was necessary to have large and well-prepared rooms available. 3.3.2. Feedback for the trade union, employers’ association, and specialist technical school teachers The organizing group including members from the trade union and employers’ association (four individuals in total), the technical school teachers (two individuals), four supervisors, and the two authors, participated in a 2-day seminar in June 2003. The evaluation was presented as lectures from the participants, semi-structured group interviews, and a concluding open discussion. All found it very promising that as many as 292 floor layers had participated in the courses. This was more than one third of the total number of floor layers in the trade union in the whole of Denmark. By contrast, only 10 floor layers had participated in courses on floor laying from a standing position during the previous 4 years, 1997–2000, see Table 5. One of the reasons for success was reported as: ‘The organizations had felt an obligation to do something. This
is an example which shows that we can make changes if we join our forces’. The existence of sufficient and well-developed tools was mentioned as another reason for the success of the courses. The most important activities for the trade organisations have been the marketing of the courses, participation in the regional meetings, finding participants, and ensuring the funding. The employers’ association made contacts with the employers, arguing in favour of participation on the grounds that there would be a ‘fall in sick leave over time’, and because the tools would be provided free of charge. When they were contacted, most employers were supportive. It was the first time that the technical school had used supervisors. There had been a lot of worry about the issue: Are supervisors able to teach their colleagues following a 14-day course. They therefore tried to plan the courses for each of the supervisors as a series, so that they would not have to start afresh each time. The organizing group found that the use of supervisors had had a very positive effect on the process. 3.4. Time study and quality study The results from the time study and quality study are shown in Table 3. When calculating the work tasks as an average of all work task registered, the traditional and the new working method used nearly the same amount of time.
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At one work place, gluing was done faster in an upright working-position for both the floor layer and the supervisor, on the second it was done slower by both workers, and for the last work place it was faster for one and slower for the other floor layer. Priming and intersection was also done faster for some and slower for others. Welding was done faster with the new working method at all work places and by both floor layers and supervisors. When comparing the traditional and the new working methods the quality of none of the work tasks differed significantly. Nearly all tasks were with small cosmetic or insignificant failures. 4. Discussion The study showed an increased frequency of floor layers using the new working methods during the implementation. The new working methods reduced the degree of knee complaints comparing floor layers who did change their working methods with those who did not, and the use of the new working methods did not increase the complaints elsewhere. The quality of the work and the time used was the same using traditional and new working methods. The hypothesis of the study was therefore confirmed, except that the time taken using the new working methods did not show any decrease. It cannot be assumed that the success of the changed working methods will be sustained when the highly motivated experts and the unions are withdrawn from the intervention process. The study has to be evaluated within three months after the training because of a demand from one of the foundations. However, it would have been better to make an assessment of the outcome-variables repeatedly over a period of more than 1 year, to test these preliminary results, as suggested by Westgaard and Winkel (1997). 4.1. Evaluation of the process In earlier studies, it has proved difficult to induce employers and their employees to adopt new technologies (Ringen and Stafford, 1996; Schneider, 1995; van der Molen et al., 2005). Changes have been introduced successfully if the methods were found to be relevant from the workers’ point of view or if they were the result of regulations from the authorities (Ringen et al., 1995). The changes reported in this study succeeded as a result of a combination of several different factors. The main stimulus to the process had been repeated scientific reports about the harmful health effects on the musculoskeletal system which result from working in a kneeling position; these reports have been presented repeatedly to the trade organizations, the employers, the floor layers, the apprentices, and the technical school teachers. It can be assumed that a collective understanding has consequently been created about the general health problems which result from working in kneeling positions. Additionally, the trade has experienced increasing problems in its efforts to recruit
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new floor layers and has an increasing need to retain skilled floor layers in the trade. Successful implementation of change is more likely to be achieved when workers and their unions take the initiative, and consequently are self-motivated to make improvements. It was therefore considered to be important to establish a feeling of ownership of the project, to use local experts and to signal from the beginning of the project that there was an agreement in support of the project between the trade union and the employers’ association, the employers, and the employees. The positive findings in this study strengthen support for the power of participative ergonomics approaches which was found in other studies (De Jong et al., 2003; Haines et al., 2002; Westgaard and Winkel, 1997). In this study, the role of the trade organizations was considerable, and there was mutual agreement about the policy, strategy, and attitudes. This was the basis which enabled sufficient information about the project to be given to the floor layers and their employers, for the high participation rate at the regional meetings and at the courses, and for the funding for the provision of tools freeof-charge to the participants. The results from the study showed that, from 2000 till 2003, there was an increase from 13% to 48% in floor layers who had tried the new tools. The implementation had therefore been an ongoing process, and the time may therefore have been the ripe for a more substantial goaldirected effort. This study also indicates the importance of developing the right tools, which, as in this case, prove to be effective and easy to use. It also points to the value of experience with the tools, both theoretical and practical, becoming well established among the technical school teachers. These findings are also supported by other studies (Schneider, 1995; Robertson and O’Neill, 2003). Establishing the correct size and the best organisation of the courses, especially the selection and the use of the supervisors, may also have played a positive role. These initiatives were necessary if a large number of floor layers were to be trained in a short time. It is also seen as positive that it was fellow-floor-layers, who were recognised as knowing the trade as insiders, who did the training and acted as role models. It is possible that the central role of the supervisors has promoted the feeling of ownership of the project. The local champions have in this way played a more active role, and had more individual responsibility than is typically found in intervention studies. It was also of great importance that the floor layers could keep the tools as their own property after the courses. This may have prevented the problems which could have arisen if the floor layers had experienced difficulties in obtaining the tools, and it meant that the floor layers were able to use the new working methods immediately after the courses, if their ongoing work included relevant tasks. This has been confirmed in this project.
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A positive climate for the intervention process and the results may in this study be provided by favourable combinations of different factors in the trade, such as good collaboration between the researchers, trade unions and training organizations, development of new tools which were accepted by the employees, provision of the tools free of charge, the ‘train the trainer’ approach, the mutuality of interests and policies amongst employers and the employees and their unions, and widening support for health and safety initiatives. To ensure that the process continues within the floor lying trade, it will be important to follow-up with further initiatives. The trade organizations have already decided that, in the future, apprentices should be provided with the new tools in their toolboxes, and the training courses are now obligate for apprentice floor layers. It will also be necessary to provide more courses, to follow-up the courses which have already been completed, and to arrange new courses for floor layers who have not yet participated. 4.2. Evaluation of the effects 4.2.1. Experience with the new working methods There was an increase in the use of the new tools from 13% in 2000, to 48% before the courses and 86% after the courses. The frequency of floor layers using the new tools weekly/daily especially increased (from 11% to 43%) after the courses. This indicates that the courses had a very substantial effect on the frequency of using the tools. This study indicates that ergonomic intervention can diminish exposure to kneeling work tasks. In an earlier study, we found that knee-straining work tasks in the floor layers’ trade constitutes 56% of the work time (Jensen et al., 2000a, b). It is possible to carry out a large part of the work tasks from an upright position by using the new working methods. In the interviews, the floor layers reported that 50–60% of these work tasks can now be carried out from an upright position. By taking these reports into account, the use of the new working methods can reduce the total amount of knee-straining activity from 60% to approximately 30%. This level corresponds to the amount of knee-straining work activity for carpenters (Jensen et al., 2000a; Holmstro¨m et al., 1995) or plumbers and pipe fitters (Eenberg et al., 2002). Prior to this study, the floor layers were concerned about not having time for training new working methods. They were also concerned about the risk of reducing the quality of their work. The time study showed that the time used for a particular task was at least as fast when using the new methods as when using the traditional working method. More than half of the floor layers participating in the questionnaire study even reported the new methods to be faster, especially when priming. The quality of the work showed no significant differences when comparing the new and the traditional methods. These results suggest (bearing in mind that the observation time was short) that the new working methods in higher degree were used after training, did not
decrease the quality of work and were as fast as the traditional work methods. 4.2.2. Improvement of the musculoskeletal complaints Prior to the courses, the floor layers had been concerned about the possibility of getting more pain in their elbows and shoulders when using the new tools. Many floor layers with musculoskeletal complaints reported reduction in complaints, including neck, shoulders, wrists, and knees after the courses. However, bearing in mind the short observation time in this study, the results may indicate that the new working methods do not produce new health problems in other parts of the musculoskeletal system. Long-term effects on the musculoskeletal system cannot be determined from our present results. A follow-up study after 1–2 years is necessary to look at longer-term effects. To document a hoped-for decrease in the prevalence of knee osteoarthritis, the follow-up period may need to be even longer, probably several or even many years. Floor layers, who used the new working methods weekly or daily, had a reduction of knee pain compared to floor layers using the new working methods occasionally or never. However, it is possible that the group which changed its working methods was more satisfied, and consequently reported better outcomes, such as less musculoskeletal pain, than the group which did not use the new methods. The reduction showed a dose–response relationship which supports the suggestion that there may be a real relationship. Reports of less pain in the musculoskeletal system by the floor layers using the new tools were only evident for the complaints of pain in neck, shoulder, wrist and the knees and not from the rest of the body (elbows, upper and low back, hips, and feet), and this contradicts this argument. The outcome sustainability might be assessed by repeated observations after a period of more than 1 year, and it would be relevant at that time to include a control group which has not participated in the first part of the study when comparing the musculoskeletal complaints as suggested by Westgaard and Winkel (1997). These results indicate (bearing in mind that the observation time was short) that the new working methods may reduce the musculoskeletal complaints and that they do not produce new health problems. 5. Conclusion An implementation of new working methods in the floor layer trade succeeded when floor layers were trained in new working methods by the trainer approach combined with information and facilitation. A 3 months evaluation showed a reduction in knee complaints comparing floor layers who did change their working methods with those who did not. The use of the new working methods did not result in musculoskeletal problems in elbows, wrists, upper or low back or in other parts of the musculoskeletal system. The new working methods were as productive as the
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