Factorial analysis of lifting task to determine the effect of different parameters and interactions

摘要

Purpose - The purpose of this paper is to evaluate the effect of main parameters and their interactions on the workers' Lifting Index in a steel rolling mill. Design/methodology/approach - NIOSH (National Institute for Occupational Safety and Health) lifting equation has been used to evaluate the risk of lifting tasks with respect to low back injury under varying load (10, 15, 20 kg), frequency (2, 3, 4 lifts/min), and twisting angle (0, 30, 45 degree). Findings - The level of importance of the parameters on lifting index at origin and destination has been determined using analysis of variance (ANOVA). The analysis draws on lifting parameters and uses both main effects and interactions to describe the variation in Lifting Index and to identify the social influence associated with back injury. The interactions between object weight and twisting angle and object weight and lifting frequency turn out to be significant (p < 0.05), whereas the interaction between twisting angle and lifting frequency is less significant (p = 0.061). Research limitations/implications - The study includes a specific location (steel rolling mills located in Jammu region of India) only. Practical implications - The findings suggest that focus should be made on all lifting parameters, rather than sole emphasis on the load to be lifted. Originality/value - The paper supports the view that load, twisting angle and lifting frequency greatly influence the physical stressfulness of the task. It is suggested that the workplace should be designed for negligible twisting and moderate lifting frequency, so as to have minimum Lifting Index.