The purpose of this study was to determine whether a specific threshold per lifting movement, the accumulation above which best predicts lumbar disk protrusion, exists or the total lifting load should be considered. This was a retrospective study. Subjects with various lifting exposures were recruited. Disk protrusion was assessed by magnetic resonance imaging. The cumulative lifting load was defined as the sum of the time-weighed lumbar load for each job and was calculated using a biomechanical software system. The effectiveness of accumulation above different thresholds in predicting disk protrusion were compared using four statistical methods. A total of 252 men and 301 women were included in the final analysis. For the men, 3000 Newtons for each lifting task was the optimal threshold for predicting L4-S1 disk protrusion, whereas for the women, 2800 Newtons was optimal. Our findings suggested that for cumulative lifting exposure, including the total lifting load without defining a minimal exposure limit might not be the optimal method for predicting disk protrusion. The NIOSH 3400 Newton recommended limits do not appear to be the optimal thresholds for preventing disk protrusion. Different lifting thresholds might be needed for men and women in the workplace for their safety.

中文翻译：

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腰部负荷阈值在累积举重暴露以预测亚洲人群椎间盘突出中的作用

这项研究的目的是确定是否应考虑每个举升运动的特定阈值（高于该阈值可以最好地预测腰椎间盘突出）或总举升负荷。这是一项回顾性研究。招募了各种举重暴露的受试者。通过磁共振成像评估椎间盘突出。累积的起重负荷定义为每个作业的时间加权腰部负荷之和，并使用生物力学软件系统进行计算。使用四种统计方法比较了不同阈值以上的积累在预测椎间盘突出中的有效性。最终分析中总共包括252名男性和301名女性。对于男性而言，每次举重任务需要3000牛顿是预测L4-S1椎间盘突出的最佳阈值，而对于女性而言，2800牛顿是最佳的。我们的研究结果表明，对于累积举升暴露，包括总举升载荷但未定义最小暴露极限，可能不是预测椎间盘突出的最佳方法。NIOSH 3400 Newton建议的限制似乎不是防止磁盘突出的最佳阈值。为了安全，工作场所的男女可能需要不同的起吊阈值。