EFFECTS OF THE COMBINATION POSTURES OF TRUNK, SHOULDER AND LEG ON PERCEIVED EXERTION IN MANUAL HANDLING TOOLS

Abstract

An expanding body of literature recognises the importance of assessing coordinated postures to overcome the possibility of under/over-assessing in the available posture’s assessment checklists. In addition, the interaction between the upper and lower limbs has yet to be considered. Therefore, this study investigates the impact of the main and combination of shoulder, trunk and leg support postures in a horizontal drilling task on the rating of perceived exertion (RPE).  A total of 10 male participants with a mean age of 23.3 ±0.7 were selected for the experiment. The general linear model (ANOVA) was used to analyse the data. Results show that shoulder flexion, trunk bending forward and leg support have significant effects on RPE (P < 0.01). Moreover, leg support reduces the discomfort for all postures with an approximate value of 1 on the Borg’s scale. The difference in RPE at a shoulder flexion angle of 45°– 90° was likewise determined to be twice of 0°–45° for all coordinated postures. These findings can be beneficial in designing tasks based on trunk, shoulder and leg support to decrease musculoskeletal disorders, save energy, and increase efficiency.