Santos et al. BMC Public Health 2011, 11:60 http://www.biomedcentral.com/1471-2458/11/60 American workers the cumulative incidence rate of upper extremity tendonitis was 24.3% during an average follow-up of 5.4 years [7]. In Brazil, accurate statistical data are scant, but according to the National Institute of Social Security (INSS), WMSD is the second most frequent cause of sick leave [2]. Treatment for WMSD has frequently shown disappointing results and prevention is regarded as the best strategy to avoid economic and social consequences [6,8-11]. Interventional preventive measures have been tested in randomized controlled trials, but results have been mixed [12-20], and the effectiveness of these programs has not been consistent. This variability could be related to the type of work, differences in training and/or educational programs, and methodological issues related to study design. To our knowledge, no previous study has evaluated the effect of a specific program aimed at the prevention of WMSD on the quality of life (QL). It may be the case that an effective educational program could improve QL for workers through teaching techniques of avoidance and controlling risk factors for WMSD. Therefore, we designed a randomized controlled trial to evaluate the impact of a specific educational program for the preven- tion of WMSD on measures of QL, particularly physical functioning, on a sample of workers from a steel trading company. Methods Study Design This was an open label randomized controlled trial of parallel groups comparing the effect on QL of a specific educational program designed for the prevention of WMSD versus a general health orientation program. The study population, recruitment and randomization The study population included clerical staff and produc- tion workers from a steel trading company located in Porto Alegre/RS/Brazil (Aços Favorit Ltda ™). All workers were involved in a routine of overcharge tasks and/or repetitive movements. The company had a total of 131 active employees (May/2008). Workers less than 18 years old, on sick leave, working night shift, on vacation or those that could not be released from their activities (most of these were supervisors), were excluded. One hundred and twenty employees were eligible for randomization, and 101 agreed to participate in the study. The company presented two lists of workers organized in alphabetic order (one list consisting of clerical work- ers and other consisting of production workers). Using WINPEPI software [21], both lists were reorganized in an aleatory sequence, and the workers were invited to participate following this sequence. Individuals that were Page 2 of 7 considered eligible for randomization (after written informed consent) were included in a numbered sequen- tial list for randomization. Therefore, two numerically ordered lists (one for clerical and other for production workers) were produced. Using the WINPEPI software, the workers within each list were randomly allocated to one of two groups (intervention or control group) (Figure 1). Interventions Subjects allocated to the intervention group attended six consecutive weekly training sessions of one hour duration at the worksite (during the working period) administered by the main investigator (ACS). The num- ber of participants in each session was limited to 25 individuals [18], and the structure of “group dynamics” (involving interaction, discussion, dramatization of daily living and work related activities) was used. The educa- tional program was applied using flip-charts and printed material (no computer-based resources were used during the sessions). The training sessions followed the schedule as described below: - First meeting: discussion of the importance of work for QL. Debate about the objectives and elements of the educational program for prevention of WMSD, the body as a major work tool, work-related and daily living overload of the musculoskeletal system, and the importance and duration of breaks. Demon- stration of some specific stretching exercises for the neck and upper extremity muscles. Distribution of didactic material (to be read as homework) reinfor- cing the issues discussed in the first meeting and introducing the topics of the next meeting. - Second meeting: review of issues discussed in the previous meeting. Demonstration and practice of breaks. Discussion of psychological and emotional stress. Orientation for the identification of risk situa- tions for WMSD in specific task jobs. Distribution of didactic material concerning strategies to identify and control stress, and pictures concerning overload tasks and bad postures. - Third meeting: discussion concerning the main objectives of ergonomics, bad postures, and overload tasks. Debate about stress and interpersonal relation- ships. Distribution of didactic material for the fourth and fifth meetings. - Fourth meeting: an interactive training with the aim to stimulating an attitude in which each worker observes and warns his colleagues (subgroups con- sisting of two or three individuals) about breaks, relaxation, stretching exercises, and good posture. - Fifth meeting: debate of physiological responses to emotional stress. Training in exercises for relaxation