Musculoskeletal exposure of manual spray painting in the woodworking industry – an ergonomic study on painters

Abstract

In the present study the ergonomic conditions of manual spray painting in the woodworking industry have been studied. Manual spray painting is, despite rationalisations, quite common in the Swedish woodworking industry. Interviews with spray painters showed that they had higher prevalence of musculoskeletal symptoms in their right shoulder compared with other workers with manual work. A majority of the spray painters painted work-pieces lying on a work-table. A majority of these painters abduct the right upper-arm so much when painting the horizontal surface of the work-piece that they risk supraspinatus tendinitis. The upper-arm abduction when painting horizontal surfaces could be decreased without introducing new ergonomic disadvantages by installing work-tables with powered height control or possibly also by changing the geometry of the spray gun. Gripping the spray gun trigger was for some of the painters identified as causing a high risk for WMSD in the wrist. Lower spray gun trigger force would improve the situation. This could be done by the users in several ways, such as greasing the trigger mechanism and/or decreasing the spring pressure on the fluid needle. Relevance to industry The study highlights some major ergonomic problems for a fairly large group of workers in the woodworking industry.