Genaidy A M, Simmons R J, Guo L, Hidalgo J A
Department of Mechanical Industrial and Nuclear Engineering, University of Cincinnati, OH 45221-0116.
Ergonomics. 1993 Apr;36(4):323-9. doi: 10.1080/00140139308967889.
For two decades, observational methods have been used to measure postural loads in industry. These methods depend on the analyst's judgment to characterize correctly the working postures. The errors associated with estimating the body part's angular deviation from the neutral position are not known. Recently, videotaping of a work situation, followed by examination of the tape to assess postural position has become more commonly practised. This study was conducted to determine the error which accompanies the judging (without tools) of postural angles. In the present study, a method was used whereby 20 subjects were asked to report the perceived angles which closely matched the actual shoulder flexion angle displayed on the TV screen. The results showed no significant differences among the three angular ranges ('low', 1-60 degrees; 'medium', 61-120 degrees; and 'high', 121-180 degrees) of shoulder flexion, in terms of algebraic and absolute errors. Subjects tended to slightly overestimate the true angle in the low range and to slightly underestimate the true angle in the medium and high angle ranges. This study suggests that visual perception can be used to estimate shoulder flexion angles displayed on a VDT.
二十年来，观察法一直被用于测量工业中的姿势负荷。这些方法依赖于分析师的判断来正确描述工作姿势。与估计身体部位相对于中立位置的角度偏差相关的误差尚不清楚。最近，对工作场景进行录像，然后检查录像以评估姿势位置的做法变得更加普遍。本研究旨在确定在（无工具）判断姿势角度时所伴随的误差。在本研究中，采用了一种方法，让20名受试者报告与电视屏幕上显示的实际肩部屈曲角度密切匹配的感知角度。结果表明，在肩部屈曲的三个角度范围（“低”，1 - 60度；“中”，61 - 120度；“高”，121 - 180度）中，代数误差和绝对误差方面均无显著差异。受试者在低角度范围内往往会略微高估真实角度，而在中角度和高角度范围内则会略微低估真实角度。本研究表明，视觉感知可用于估计VDT上显示的肩部屈曲角度。
