Burdorf A, van Riel M, Brand T
Department of Public Health, Erasmus University, Rotterdam, The Netherlands.
Am Ind Hyg Assoc J. 1997 Jul;58(7):489-97. doi: 10.1080/15428119791012586.
In a cross-sectional study, the relationship between physical load and musculoskeletal complaints was examined among operators (n = 77), office workers (n = 52), and miscellaneous workers (n = 15) in a tank terminal company. Information about history of musculoskeletal complaints, individual characteristics, and working conditions in past and present was obtained by a standardized interview. Assessment of physical load was performed by direct observation of awkward postures and forceful exertions during normal activities. Workers filled out a diary regarding the executed tasks during one shift. Physical load was also modeled by linking the average physical load of workers performing a particular task with the task distribution of each worker. The modeling approach was beneficial to estimate infrequent characteristics of physical load, whereas the observations were better for assessing frequent exposure to awkward trunk postures. After adjustment for age and other confounders the observed work time with trunk flexion and rotation was associated with the occurrence of back pain. The modeled work time with arms raised above shoulder showed a relationship with elbow pain, and the modeled work time with forceful exertions over 100 N showed relationships with elbow pain and wrist pain. The described relationships demonstrate that the assessment strategy chosen in a particular study strongly influences random measurement error of physical load, and that inappropriate strategies may mask true associations between physical load and musculoskeletal complaints. Modeling strategies offer the opportunity to assess physical load in dynamic work environments.
在一项横断面研究中，对一家油库码头公司的操作人员（n = 77）、办公室职员（n = 52）和杂工（n = 15）的身体负荷与肌肉骨骼不适之间的关系进行了研究。通过标准化访谈获取了有关肌肉骨骼不适病史、个人特征以及过去和现在工作条件的信息。通过直接观察正常活动期间的别扭姿势和用力情况来评估身体负荷。工人们填写了一份关于一个班次内所执行任务的日志。还通过将执行特定任务的工人的平均身体负荷与每个工人的任务分配相联系来模拟身体负荷。建模方法有助于估计身体负荷的罕见特征，而观察结果则更有利于评估频繁暴露于别扭的躯干姿势的情况。在对年龄和其他混杂因素进行调整后，观察到的躯干屈曲和旋转工作时间与背痛的发生有关。模拟的手臂举过肩部的工作时间与肘部疼痛有关，模拟的用力超过100牛的工作时间与肘部疼痛和手腕疼痛有关。上述关系表明，特定研究中选择的评估策略会强烈影响身体负荷的随机测量误差，而且不恰当的策略可能会掩盖身体负荷与肌肉骨骼不适之间的真实关联。建模策略为在动态工作环境中评估身体负荷提供了机会。
