Latko W A, Armstrong T J, Foulke J A, Herrin G D, Rabourn R A, Ulin S S
University of Michigan, Dept. of Industrial and Operations Engineering, Ann Arbor 48109-2117, USA.
Am Ind Hyg Assoc J. 1997 Apr;58(4):278-85. doi: 10.1080/15428119791012793.
Several physical stressors, including repetitive, sustained, and forceful exertions, awkward postures, localized mechanical stress, highly dynamic movements, exposures to low temperatures, and vibration have been linked to increased risk of work-related musculoskeletal disorders. Repetitive exertions have been among the most widely studied of these stressors, but there is no single metric for assessing exposure to repetitive work. A new methodology enables repetitive hand activity to be rated based on observable characteristics of manual work. This method uses a series of 10-cm visual-analog scales with verbal anchors and benchmark examples. Ratings for repetition reflect both the dynamic aspect of hand movements and the amount of recovery or idle hand time. Trained job analysis experts rate the jobs individually and then agree on ratings. For a group of 33 jobs, repetition ratings using this system were compared to measurements of recovery time within the cycle, exertion counts, and cycle time. Amount of recovery time within the job cycle was found to be significantly correlated with the analysis ratings (r2 = 0.58), as were the number of exertions per second (r2 = 0.53). Cycle time was not related to the analyst ratings. Repeated analyses using the new method were performed 1 1/2 to 2 years apart on the same jobs with the same group of raters. Ratings for repetition differed less than 1 point (on the 10-cm scale), on average, among the different sessions. These results indicate that the method is sensitive to exertion level and recovery time, and that the decision criteria and benchmark examples allow for a consistent application of these methods over a period of time. This method of rating repetition can be combined with similar scales for other physical stressors.
包括重复性、持续性和高强度用力、不良姿势、局部机械压力、高动态运动、暴露于低温环境以及振动在内的多种物理应激源，都与工作相关肌肉骨骼疾病的风险增加有关。重复性用力是这些应激源中研究最为广泛的，但目前尚无单一指标可用于评估重复性工作的暴露程度。一种新方法能够根据体力工作的可观察特征对手部重复性活动进行评级。该方法使用一系列带有文字锚点和基准示例的10厘米视觉模拟量表。重复性评级既反映了手部动作的动态方面，也反映了恢复或手部空闲时间的长短。经过培训的工作分析专家各自对工作进行评级，然后就评级达成一致。对于一组33项工作，将使用该系统得出的重复性评级与周期内恢复时间的测量值、用力次数和周期时间进行了比较。发现工作周期内的恢复时间长短与分析评级显著相关（r2 = 0.58），每秒用力次数与分析评级也显著相关（r2 = 0.53）。周期时间与分析人员的评级无关。使用新方法对同一组评估人员在1.5至2年的时间间隔内对相同工作进行了重复分析。不同评估期间的重复性评级平均相差不到1分（在10厘米量表上）。这些结果表明，该方法对应力水平和恢复时间敏感，并且决策标准和基准示例允许在一段时间内持续应用这些方法。这种重复性评级方法可以与针对其他物理应激源的类似量表相结合。
