Participatory ergonomics for risk reduction of musculoskeletal disorders among polishing workers in a wood furniture manufacturing factory in Chonburi province
Abstract:
Employees at the wood furniture manufacturing factory are susceptible to work-related musculoskeletal disorders due to heavy lifting, exertion, repetitive movements, and improper working posture. This research aimed to improve working conditions through participatory ergonomics for risk reduction of musculoskeletal disorders among the polishers in a wood furniture manufacturing factory. The sample group in this study comprised 13 polishers. Research instruments consist of questionnaires gathering general and operational information, questionnaires for musculoskeletal pain and pain severity, the rapid entire body assessment (REBA), electromyography (EMG) and a post-improvement employee satisfaction questionnaire. Improving working conditions consisted of activities the refinement of posture when handling the sander, lifting and placing wood planks using artificial carts, improve the position of lifting and placing wood planks on the carts for wood drying and the adjustment of the positioning of placing wooden pallets/ artificial carts and wood drying carts close to the polishing workbench. After the improvement of working conditions, the result of the study shows a reduction in the mean intensity of pain in the neck, shoulders, wrist/hand, elbows, upper back, lower back, and ankle/foot. However, no statistically significant differences. The average REBA scores for the entire body indicated a significant decrease only in the wood planks lifting activity after improvement of working conditions (p<0.001) by the mean scores REBA before improvement was 9.85±0.56 and after improvement was 4.85±1.28, whereas wood planks polishing activity the average REBA scores decreased not different from before the work condition improvement. For the evaluation of muscle contraction using EMG after the improvement revealed a decrease in the mean %MVC for the right middle deltoid muscle, left biceps brachii, left upper trapezius, and right gastrocnemius during the wood planks lifting activity, without reaching statistical significance. Similarly, during the wood planks polishing activity, a decrease in the mean %MVC was observed in the right biceps brachii, left biceps brachii, and right gastrocnemius muscles, with no statistically significant difference. Notably, employees expressed the high to highest level of satisfaction with the improved working conditions. The results show that this participatory ergonomics principle can be applied to polishers of other wood furniture manufacturing factories or other establishments with similar workflow lifting activities.