Effects of load information on biomechanical characteristics of lifting tasks

Abstract

The lower back pain caused by manual lifting is one of the most common occupational injuries. This study aims to investigate how biomechanics of lifting tasks is affected by the availability of load information. Twenty-four healthy men with lifting experience were recruited, and they were instructed to perform the lifting tasks under different weights, fragility information and lifting load conditions. The lifting load was set at three levels including light, medium and heavy. The load prompt information has four levels corresponding to "no information" , "prompt mass information" , "prompt material fragility information" and "prompt mass and material fragility information" , respectively. The results show that with the availability of material fragility information, the muscle activity of thigh and back is weakened, meanwhile, the torque of low back and the maximum angular velocity of hip joint are reduced. However, due to the longer duration of lifting, the risk of low back injuries increased instead. The prompt information about load weight has no significant influence on lower back biomechanics. The lifting load effects on lifting biomechanics are more substantial than load prompt information. This suggests that reducing lifting load should be more effective in the control of lower back pain. The experimental results can provide useful guidance for the design of safe manual lifting operation standards.