Methodological variance associated with normalization of occupational upper trapezius EMG using sub-maximal reference contractions
Methodological variance associated with normalization of occupational upper trapezius EMG using sub-maximal reference contractions
复制标题
DOI：
10.1016/j.jelekin.2007.11.004
复制
发表时间：
2009-06-01
影响因子：
2.5
通讯作者：
Dempsey, Patrick G.
中科院分区：
文献类型：
--
作者：
Jackson, Jennie A.;Mathiassen, Svend Erik;Dempsey, Patrick G.
目的：为了量化的方差引入到肌电（EMG），通过规范化的次最大参考自愿exertions（RVE），并调查的影响，增加规范化的努力相比，其他变化的数据收集策略上的精确度职业EMG estimates.Methods：妇女进行四个RVE收缩，然后由30分钟的光，循环组装工作的每两天。将工作周期EMG标准化为每个RVE试验，并计算7个暴露参数。确定了受试者、受试者内日、周期和日内标准化试验的暴露方差比例。使用这些数据，影响的曝光平均值的精确度改变的受试者，天，周期和RVES在数据collection.Results：对于所有曝光参数的方差的一个独特的组件，由于归一化是存在的，但小：小于4.4%的总方差。资源分配模拟表明，组暴露平均值的精确度的边际改善将发生在一天收集的EMG的三个RVE重复以上，或超过两个RVE收集的EMG在两个或更多天。(C)2007爱思唯尔有限公司保留所有权利。
Objectives: To quantify the variance introduced to trapezius electromyography (EMG) through normalization by sub-maximal reference voluntary exertions (RVE), and to investigate the effect of increased normalization efforts as compared to other changes in data collection strategy on the precision of occupational EMG estimates.Methods: Women performed four RVE contractions followed by 30 min of light, cyclic assembly work on each of two days. Work cycle EMG was normalized to each of the RVE trials and seven exposure parameters calculated. The proportions of exposure variance attributable to subject, day within subject, and cycle and normalization trial within day were determined. Using this data, the effect on the precision of the exposure mean of altering the number of subjects, days, cycles and RVEs during data collection was simulated.Results: For all exposure parameters a unique component of variance due to normalization was present, yet small: less than 4.4% of the total variance. The resource allocation simulations indicated that marginal improvements in the precision of a group exposure mean would occur above three RVE repeats for EMG collected on one day, or beyond two RVEs for EMG collected on two or more days. (C) 2007 Elsevier Ltd. All rights reserved.