我國人工搬運重量常數設定探討

The Load Constant in Manual Handling for Chinese Subjects

人工搬運工作已被證實為造成下背傷害主要原因之一。近年來，許多學者、政府機構、及國際組織都致力於擬訂人工搬運標準與規範，以預防人工搬運所造成之下背傷害。過去研究顯示，國人之搬運能力比美國人小。因此，美國之人工搬運重量建議值可能不適於國人。本文之目的在於探討我國人工搬運重量常數之設定。研究方法上，首先收集國內有關人工搬運重量資料，主要為以心物法所決定之最大可接受抬舉重量值。再參考美國NIOSH抬舉規範與相關文獻資料，設定重量常數。研究結果發現國人之重量常數年輕男性約為24 公斤（99%），女性為17公斤（75%）。然而，美國NIOSH推薦重量常數為23 公斤，此一推薦值適用於99%男性與75%女性。此一差異可能是本研究使用的箱寬為36 公分，使用較小箱寬，會獲得較大的MAWL值。其次，不同族群可能會有不同。

It has been proven that manual handling task is one of the main risk factors that cause low back injuries. Therefore, increasing effort were made in recent years by individuals, governments, and international organizations to produce standards and regulations for the prevention of musculoskeletal disorders resulting from manual handling. Previous studies of lifting capacities of Chinese subjects have shown that when compared with the data of Caucasian subjects, Chinese subjects have the statistically significant smaller maximum acceptable weight limits (MAWLs). The 2 weight limits that recommended in the NIOSH lifting guide might not fit Chinese subjects. The purpose of this study was to aim toward exploring the load constant in manual handling for Chinese subjects. In this study, the information on the MAWLs especially determined by psychophysical method for Chinese subjects were first collected. Subjects were sixty-four young male and twelve young female. Then, the load constant that could be the weight limits under ideal conditions was chosen according to the revised NIOSH lifting equation and previous studies. The results showed that the load constant calculated from the MAWLs were 24 Kg for 99% young male and 17 Kg for 75% female, respectively. However, the load constant from the NIOSH lifting equation was 23 Kg for 99% of men and at least 75% of women. A discussion for the difference between the load constant obtained in this study and that recommended in the revised guide was shown as following. The first possible explanation for the discrepancy was that the width of lifting box used in this experiment was 36 cm. When the smaller box was used, the MAWLs might be bigger. The second reason for the difference might be the different populations that were taken in the studies.