下背部傷痛生物力學模式之評估研究

A Study on Biomechanical Model for Low Back Pain

抬舉動作時在L5/S1的椎間盤部位受力最大引起下背部傷痛，因此以生物力學模式制訂抬舉極限值時，便是以此部位所能承受的最大值作為抬舉重量的極限值。美國職業安全衛生研究所（NIOSH）的研究指出，當L5/S1 椎間盤所受之力超過 3400牛頓時，對某些工作者將存在相當的傷害風險，且當L5/S1椎問盤所受之力超過 6400牛頓時，將對大部分的工作者造成傷害，因此，目前大多以此兩個數值作為評佔下背傷害的參考標準。 本研究以下背痛門診病人為對象，透過醫院醫師的問診，篩選出與工作相關的下背痛患者，再由研究人員以問卷訪談方式，過濾出 38 名從事非頻繁性抬舉工作者。經由對患者訪談與抬舉動作分析，廣泛的收集相關資料，使用勞工安全衛生研究所87年度研發的二維生物力學模式電腦程式與評估圖，計算38名下背痛患者L5/S1椎間盤受力，並探討評估圖之適用性。研究結果發現下背痛患者抬舉過程L5/S1椎間盤之最大受力平均值為4785牛頓且標準差為1916牛頓，其中男性與女性之最大受力平均值分別為5155牛頓與3878牛頓。假設本次研究數據為常態分布，結果顯示因抬舉不當引起之下背痛，大約24%的患者L5/Sl椎問盤受力之最大受力低於 3400 牛頓。另外，研究發現勞工安全衛生研究所開發之生物力學模式評估圖，可被作為工作設計的參考工具，減少傷害發生及金錢損失，對抬舉工作者與業主均有助益。

Most of the studies of low back pain (LBP) caused by lifting action, use biomechanical models to find lifting limits. The primary biomechanical criteria used is based upon maximum compression on L5/SI disc, because the L5/SI disc has the potential to incur the greatest moment in lifting and is one of the most vulnerable tissues. According to NIOSH's report, workers with predicted compressive force more than 3400N have higher risk of back problem, and most workers may suffer from back injury while the force reaches 6400N. Therefore, most studies adopt these two numbers, 3400N and 6400N, as criteria for LBP risk assessment. By investigating manual lifting for LBP outpatients, a feasibility study on using evaluation diagrams for reduction of work-related LBP was carried out. Through medical doctors' interrogations, the work-related LBP patients can be filtered out. Further interviews/questionnaires conducted by researchers were followed immediately. 38 patients who performed infrequent task were chosen as subjects in this study. Ali information needed for evaluation was collected extensively through interviews and posture analyses. Using computer program developed by the Institute of Occupational Safety and Health (IOSH) in 1998, an investigation on compressive force on L5/S1 disc for Chinese LBP workers is presented. This study found a mean value of 4785N with a standard deviation of 1916N, while the mean value of male and female are 5155N and 3878N, respectively. These results suggest that, if the data were normally distributed, approximately 24% of the workers who suffer LBP due to lifting had ultimate compression strength of less than 3400N. In this study we found a biomechanical based evaluation diagram, designed a few years ago by IOSH, may be adopted as a reference for work design to reduce physical pain and financial loss.