Biomechanical exposure of industrial workers – Influence of automation process

Abstract

Automated processes in industry have been implemented in order to get higher production rates, but our knowledge about their effects on physical exposure of the workers is still limited. Muscular load, postures, and movements of the head, neck/shoulders, upper arms, and wrists were recorded in 19 operators from two different car clutch disc production lines (manual and semi-automated). Higher angular velocities of the head, upper back, and upper arms were found on the manual production line (on average 20% higher than the semi-automated). Upper trapezius, and forearm extensor rest (% time), as well as hand kept still (% time) were also higher on the manual production line. No difference was found regarding posture, muscular activities, and repetitiveness. The manual line had more rest, but more vigorous movements considering angular velocities. The semi-automated line, therefore, implied a higher production rate with lower angular velocities but fewer opportunities for rest than the manual line. While different physical exposures were found when comparing these two production lines with different levels of automation, the health effects derived from industrial automation ought to be investigated with a larger sample size. Relevance to industryThe reduction of rest opportunities observed on a semi-automated production line requires the attention of ergonomists when planning or redesigning tasks in such production lines. Lack of rest is considered a risk factor for the development of musculoskeletal disorders.