重物认知信息对搬举任务生物力学特性的影响

Effects of load information on biomechanical characteristics of lifting tasks

手工搬举导致的下背疼痛是最常见的职业损伤之一.为了解在手工搬举任务中,不同的重物认知信息对搬举生物力学特性的影响,招募24名有搬举工作经验的健康男性,完成在不同重物认知信息(质量提示信息和易碎性提示信息)和重物质量组合情况下的搬举任务.重物提示信息设置了无信息、质量信息、易碎信息、同时提示质量和易碎信息4个水平.重物质量设置了轻、适中和重3个水平.分析结果显示,在提示易碎信息的情况下,受试人大腿和背部的肌肉活动减弱,下背力矩及髋关节最大角速度减小;随着搬举动作持续时间延长,下背受伤的风险增高;质量信息对下背生物力学无显著的影响;与认知信息相比,重物质量对搬举生物力学表现的影响更大.因此,相比给予重物信息提示,控制搬举负重是保障搬举工人腰背健康更有效的方式.研究结果可为制定安全手工搬举作业标准提供参考.

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.