Participatory ergonomics is an intervention strategy acting on physical load exposures occurring in occupational settings, scarcely known in Spain but with a number of experiences and evidences coming from other countries. There are several reasons justifying the interest of this approach. First, participatory ergonomics focuses on one of the categories of occupational exposures with the largest impact on workers' health in a majority of countries all over the world, in terms of incidence, prevalence and disability. Secondly, basic principle in participatory ergonomics is empowerment of workers for them to participate identifying risks and injuries caused by physical exposures at work as well as proposing and evaluating proper control measures for each situation. Thirdly, it allows dealing and solving a number of problems without the use of complex technical protocols. From a public health perspective, participatory ergonomics is a largely tried model of community empowerment for the control of (occupational) factors affecting health and wellbeing. In this paper we revise some basic principles of participatory ergonomics, we comment on the keys leading to success or failing of the interventions and we present some main results coming from participatory ergonomics experiences developed for a long time in countries such as Canada, United Kingdom, Netherlands or Finland.

Most of musculoskeletal symptoms and physical demands self-reported by the workers in the questionnaire were not included in the companies' routine health surveillance and risk assessment reports. The questionnaire is a more sensitive tool than routine health surveillance and risk assessments practices in order to identify perceived problems by workers.

We describe a participatory ergonomics program that started in April 2010 in a chemical company located in the autonomous region of Valencia, Spain. The program was introduced in the company, the intervention level was agreed (two working lines, 24 workers) and a working group was established (Ergo Group, including managers, technicians and safety representatives in the company) with the aim of leading the intervention. A questionnaire was applied to collect information on ergonomic injuries and exposures in workers at the selected working lines. This information was analyzed by the Ergo Group and was later discussed at prevention circles with the direct participation of affected workers. When the present article was being drafted, 16 improvements to working conditions had already been proposed. Some of these improvements had been implemented and, in the opinion of some of the participants, were effective. To develop this kind of program, which could benefit a substantial number of workers in Spain, a firm commitment to prevention by companies is required.