Identifying Safe Load Moment Exposures for the Back

下背痛（LBP）仍然代表着 工人经历的与职业有关的肌肉骨骼疾病。 先前的监测研究（Marras等人，1993年;1995年）指出， 职业相关性腰痛风险最可靠的个体标志物是 载荷力矩（载荷大小x距脊柱的距离）。即使是这种粗糙的测量 能够在计算上更复杂的评估工具， 作为NIOSH提升指南和修正公式（Marras等人，1999）。在 此外，许多生物力学研究表明， 代表了一个生物学上合理的途径，为腰部损伤机制。 然而，没有研究试图具体定义这种关联， 之间的各种组成部分的负载力矩暴露和LBP的风险。因此 本研究的目的是探讨如何暴露于各种成分的 负载力矩（即占空比的分量）与LBP风险有关。这一目标 将通过开发和分析一个丰富多样的数据库来完成 其中时刻的大小以及时间暴露变化。两 要实现这一目标，需要分阶段进行。第一阶段将使用现有的 515个制造业职位的数据库，以帮助了解 负载力矩和暴露频率。将建立统计模型， 测试以帮助了解哪些特征的时间暴露的时刻 可以采取敏感措施。此外，仪器仪表将 精确监测负载力矩暴露。的最后组成部分 第一阶段将涉及招聘所需的各种配送中心， 建立预期数据库（第二阶段）。第二阶段将利用这一时刻 测量仪器在材料处理的工业研究。在 这项前瞻性研究将对1200名参与者进行临床监测， 在18个月的开始和结束时，LBP状态的相关指标 暴露期。在暴露期间，工作场所的组成部分将 包括精确的负载力矩暴露， 曝光（例如占空比、累积曝光等），负载位置等。 工人将被监视超过8小时轮班。完成后 前瞻性观察期，损伤报告，临床背部变化 状态等将作为荷载力矩和时间的函数进行评估 使用统计模型的暴露特征。此外，易于测量 将制定最具预测性的模型措施的替代指标， 这些发现可以用来评估风险，用最少的设备。 总的来说，这项研究不仅将提高我们对接触如何的认识， 负载力矩的各个方面影响LBP风险，但也会导致 具有高灵敏度和特异性的适用措施，用于控制 工作场所的风险。

Low back pain (LBP) continues to represent the leading occupationally-related musculoskeletal disorder experienced by workers. Previous surveillance studies (Marras et al., 1993;1995) have indicated that the most robust individual marker of risk for occupationally-related LBP is load moment (load magnitude x distance from the spine). Even this crude measure is capable of out performing more computationally complex assessment tools such as the NIOSH lifting guide and revised equation (Marras et al, 1999). In addition, many biomechanical studies suggest that the load moment exposure represents a biologically plausible pathway for a low back injury mechanism. However, no studies have attempted to specifically define the association between a various components of load moment exposure and LBP risk. Thus, the objective of this study is to explore how exposure to various components of load moment (i.e. components of the duty cycle) relate to LBP risk. This goal will be accomplished by developing and analyzing a rich and diverse database where the magnitude of the moments as well as the temporal exposure vary. Two phases will be necessary to complete this goal. Phase I will use an existing database of 515 manufacturing jobs to help understand the relationship between load moment and exposure frequency. Statistical models will be constructed and tested to help understand which features of the temporal exposure to moment might provide sensitive measures. In addition, instrumentation will be developed to precisely monitor load moment exposure. The final component of Phase I will involve the recruitment of various distribution centers needed to create a prospective database (phase II). Phase II will employ the moment measurement instrumentation in an industrial study of materials handling. In this prospective study, 1200 participants will be monitored for clinically relevant indicators of LBP status at the beginning and the end of an 18-month exposure period. During the exposure period, components of the workplace will be monitored including precise load moment exposure, temporal aspects of exposure (e.g. duty cycle, cumulative exposure, etc.), load position, etc. Workers will be monitored over an 8-hour shift. Upon completion of the prospective observation period, injury reporting, changes in clinical back status, etc. will be evaluated as a function of the load moment and temporal exposure characteristics using statistical models. In addition, easily measured surrogate indicators of the most predictive model measures will be developed so that these findings can be used to assess risk with minimal equipment. Collectively this study will not only enhance our knowledge of how exposure to various aspects of load moment affects LBP risk but will also lead to applicable measures with both high sensitivity and specificity for control of risk in the workplace.