Liberty Mutual Research Institute for Safety, 71 Frankland Rd., Hopkinton, MA 01748, USA.
Hum Factors. 2011 Aug;53(4):371-82. doi: 10.1177/0018720811410976.
The objective was to evaluate the validity and interrater reliability of a video-based posture observation method for the major body segment angles during asymmetric lifting tasks.
Observational methods have been widely used as an awkward-posture assessment tool for ergonomics studies. Previous research proposed a video-based posture observation method with estimation of major segment angles during lifting tasks. However, it was limited to symmetric lifting tasks. The current study extended this method to asymmetric lifting tasks and investigated the validity and the interrater reliability.
Various asymmetric lifting tasks were performed in a laboratory while a side-view video camera recorded the lift, and the body segment angles were measured directly by a motion tracking system. For this study, 10 raters estimated seven major segment angles using a customized program that played back the video recording, thus allowing users to enter segment angles. The validity of estimated segment angles was evaluated in relation to measured segment angles. Interrater reliability was assessed among the raters.
For all the segment angles except trunk lateral bending, the estimated segment angles were strongly correlated with the measured segment angles (r > .8), and the intraclass correlation coefficient was greater than 0.75.
The proposed observational method was able to provide a robust estimation of major segment angles for asymmetric lifting tasks based on side-view video clips. The estimated segment angles were consistent among raters.
This method can be used for assessing posture during asymmetric lifting tasks. It also supports developing a video-based rapid joint loading estimation method.
评估一种基于视频的姿势观察方法在评估不对称举重任务中主要身体节段角度的有效性和评分者间可靠性。
观察方法已被广泛用作人体工程学研究中的一种不良姿势评估工具。先前的研究提出了一种基于视频的姿势观察方法，用于估计举重任务中的主要节段角度。然而，该方法仅限于对称举重任务。本研究将该方法扩展到不对称举重任务，并对其有效性和评分者间可靠性进行了研究。
在实验室中进行各种不对称举重任务，同时使用侧视摄像机记录举重过程，并使用运动跟踪系统直接测量身体节段角度。在这项研究中，10 名评分者使用一个自定义程序来估计七个主要节段角度，该程序可以回放视频记录，从而允许用户输入节段角度。评估了估计节段角度与测量节段角度之间的有效性。评估了评分者之间的评分者间可靠性。
除了躯干侧向弯曲之外，所有节段角度的估计节段角度与测量节段角度高度相关（r>.8），且组内相关系数大于 0.75。
所提出的观察方法能够基于侧视视频片段提供对不对称举重任务中主要节段角度的可靠估计。评分者之间的估计节段角度具有一致性。
该方法可用于评估不对称举重任务中的姿势。它还支持开发基于视频的快速关节载荷估计方法。
