Prospective study on shoulder symptoms among kitchen workers in relation to self-perceived and observed work load.

OBJECTIVES: To study the occurrence of shoulder symptoms among professional kitchen workers, and whether reduction in self-perceived and observed physical work load decreases future symptoms. METHODS: In this prospective study conducted in 2002-2005 in municipal kitchens in Finland, changes during a 1-year follow-up in the physical strenuousness of work tasks were self-assessed by 376 female workers (substudy I). Changes in exposure to manual lifting and awkward upper arm posture during the follow-up were also observed by experts in 69 kitchens with 183 workers (substudy II). Information on shoulder symptoms was collected with questionnaires at baseline and at follow-up. The risk of shoulder symptoms at follow-up related to changes in exposure was estimated with logistic regression. RESULTS: The 3-month prevalence of shoulder pain was 34% at baseline and 41% at follow-up. Reduction during follow-up in work tasks perceived as the most strenuous physically (ie, receiving and storing raw food) led to a significantly reduced risk of future shoulder pain with an adjusted odds ratio (OR) of 0.41 (95% CI 0.17 to 0.98) and trouble caused by the pain with an OR of 0.34 (0.14 to 0.83). The observed reduction in lifting was also associated with a lower risk for future shoulder symptoms. CONCLUSIONS: Reduction in lifting showed beneficial protective effects on the shoulder. Although more risk factor and intervention studies are needed to estimate the health impacts of kitchen work, special attention should be paid to work tasks that include lifting when assessing risk and designing preventive measures.

A randomised controlled trial on whether a participatory ergonomics intervention could prevent musculoskeletal disorders.

OBJECTIVES: To examine the efficacy of a participatory ergonomics intervention in preventing musculoskeletal disorders among kitchen workers. Participatory ergonomics is commonly recommended to reduce musculoskeletal disorders, but evidence for its effectiveness is sparse. METHODS: A cluster randomised controlled trial among the 504 workers of 119 kitchens in Finland was conducted during 2002-2005. Kitchens were randomised to an intervention (n = 59) and control (n = 60) group. The duration of the intervention that guided the workers to identify strenuous work tasks and to seek solutions for decreasing physical and mental workload, was 11 to 14 months. In total, 402 ergonomic changes were implemented. The main outcome measures were the occurrence of and trouble caused by musculoskeletal pain in seven anatomical sites, local fatigue after work, and sick leave due to musculoskeletal disorders. Individual level data were collected by a questionnaire at baseline and every 3 months during the intervention and 1-year follow-up period. All response rates exceeded 92%. RESULTS: No systematic differences in any outcome variable were found between the intervention and control groups during the intervention or during the 1-year follow-up. CONCLUSIONS: The intervention did not reduce perceived physical work load and no evidence was found for the efficacy of the intervention in preventing musculoskeletal disorders among kitchen workers. It may be that a more comprehensive redesign of work organisation and processes is needed, taking more account of workers' physical and mental resources.