An Investigation of the Maximum Acceptable Weight of Lift by Indonesian Inexperienced Female Manual Material Handlers

Abstract

The purpose of this study was to investigate the maximum acceptable weight of lift (MAWL) by Indonesian inexperienced female manual material handlers. Twenty-one females who were selected based on their physical activity categories voluntarily participated in this study. The participants were asked to determine their MAWLs using the psychophysical method for the lifting tasks at two different lifting frequencies: one lift/5 min and 4 lifts/min. The participants’ heart rate was also recorded to be utilized for investigating the physiological responses while lifting the obtained MAWLs. The obtained MAWLs were also compared to the MAWLs of other study populations, using published data. As the results, two-way analysis of variance test result revealed no significant effect of physical activity category on MAWL (p = 0.890). On the other hand, a significant effect on MAWL for the lifting frequency was observed at p < .001. The comparison of MAWLs obtained in this study to other studies showed that no significant differences on MAWL were found between Indonesian and Chinese inexperienced manual handlers for the lifting tasks at one lift/5 min. The significant differences on MAWL were observed between Indonesian inexperienced and American experienced female manual handlers. However, no significant differences were observed for the lifting tasks at 4 lifts/min. Furthermore, the physiological data analysis revealed that the energy expenditures required for lifting at one lift/5 min was significantly less than the physiological limit, while those of lifting at 4 lifts/min was significantly higher than the limit. The results of this study might be utilized as consideration for determining the safety lifting limit for Indonesian inexperienced female manual material handlers.