Variability in mechanical exposure within and between individuals performing a highly constrained industrial work task
Variability in mechanical exposure within and between individuals performing a highly constrained industrial work task
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DOI：
10.1080/0014013031000090125
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发表时间：
2003-06-20
期刊：
影响因子：
2.4
通讯作者：
Forsman, M
中科院分区：
文献类型：
--
作者：
Mathiassen, SE;Möller, T;Forsman, M
暴露变异性数据是设计和解释职业工效学研究的重要补救措施。本研究的目的是检索内和之间的几个机械暴露参数在一个重复的，短周期的任务方差。七名经验丰富的操作员使用两种类型的手持式螺母扳手反复固定接头。接头被放置在机架上的三个不同位置，模拟汽车装配。双侧肌肉活动，从上臂伸肌和下臂，以及头部和上臂倾斜度进行了连续监测。使用ANOVA在几个数据子集中评估暴露水平及其方差分量。结果进行了解释的统计精度和权力，并讨论了重要的人体工程学素质的标志。在所有关节位置和两种工具中，受试者内和受试者之间发现了显著的暴露差异。对于跨工具和位置的混合工作，达到组平均暴露的必要受试者数量（95%置信限对应于平均值的+/- 10%）范围在8到158之间，姿势记录往往需要比肌肉活动记录更少的人群。受试者内的方差增加了2至37倍，这取决于曝光参数，当工作被“扩大”，从一个指定的位置和工具的securings的所有位置和工具的组合。受试者在变异性和对“工作扩大”的反应性方面的系统差异表明了个体化的运动控制策略。结果说明了曝光变异性数据的重要性，以设计适当的测量策略。他们还建议，暴露可变性本身的大小可以被解释为被认为是重要的人体工程学风险指标的操作指数，例如重复操作的“相同性”和灵活工作技术的容差。
Data on exposure variability is an important remedy for designing and interpreting studies of occupational ergonomics. The present study aimed at retrieving the within- and between-subjects variance of several mechanical exposure parameters in a repeated, short-cycle task. Seven experienced operators repeatedly secured joints using two types of hand-held nutrunners. The joints were placed in three different locations on a rack, simulating automotive assembly. Bilateral muscle activity from the upper trapezius and the lower arm extensors, as well as head and upper arm inclination was continuously monitored. Exposure levels and their variance components were assessed in several data subsets using ANOVA. The results were interpreted in terms of statistical precision and power, and discussed as markers of important ergonomic qualities. A substantial exposure variability was found within and between subjects in all joint locations and for both tools. For mixed work across tools and locations, the necessary number of subjects to arrive at a group mean exposure with 95% confidence limits corresponding to +/- 10% of the mean ranged between 8 and 158, with posture recordings tending to require smaller populations than muscle activity recordings. Within-subject variance increased 2- to 37-fold, depending on exposure parameter, when work was 'enlarged' from securings with a specified location and tool to a mix of all locations and tools. Systematic differences between subjects in variability and responsiveness to 'work enlargement' indicated individualized motor control strategies. The results illustrate the importance of exposure variability data to the design of proper measurement strategies. They also suggest that the sizes of exposure variability per se can be interpreted as operational indices of what is thought to be important ergonomic risk indicators, such as the 'sameness' of repeated operations and the allowance for flexible working techniques.