Reliability and validity of the WATSMART three-dimensional optoelectric motion analysis system.
Reliability and validity of the WATSMART three-dimensional optoelectric motion analysis system.
复制标题
WATSMART三维光电运动分析系统的可靠性和有效性。
作者：
J. Scholz
在静态和动态条件下评估了WATSMART（滑铁卢空间运动分析记录技术）系统的可靠性和有效性。在实验 1 中，红外发光二极管 (IRED) 放置在临床测角仪的轴和臂上。以 5 度增量的 12 个角度在三个空间位置中的每一个位置各记录 10 次。使用组内相关系数（ICC）和方差分析程序来评估可靠性，以确定试验内的变异性。所有空间位置的 ICC 均超过 0.99。在所有情况下，每个角度的 95% 置信区间均小于 0.5 度。通过回归分析评估标准参考工具的有效性。对于每个空间位置，重建角度相对于参考角度的回归斜率接近一致。然而，当测角仪远离摄像机旋转 45 度时，系统误差明显增加。在实验 2 中，机械臂配备了四个 IRED，并在三个空间位置中的每一个位置重复定义的运动轨迹 10 次。每个轨迹部分的 ICC 范围为 0.20 至 0.99。结果表明，如果采取足够的预防措施来减少不需要的光反射，则可以从该运动分析系统获得可靠且有效的结果。当物体旋转得远离安装摄像机的平面时，可靠性和有效性有所下降。
Reliability and validity of the WATSMART (Waterloo Spatial Motion Analysis Recording Technique) system was evaluated under static and dynamic conditions. In experiment 1, infrared light-emitting diodes (IREDs) were placed at the axis and along the arms of a clinical goniometer. Twelve angles in 5-degree increments were each recorded 10 times at each of three spatial locations. Reliability was assessed using intraclass correlation coefficients (ICCs) and analysis-of-variance procedures to determine within-trial variability. The ICCs for all spatial locations exceeded .99. The 95% confidence interval for each angle was less than 0.5 degree in all cases. Criterion-referenced instrument validity was assessed with regression analysis. Slopes of the regression of reconstructed angle on reference angle were close to unity for each spatial location. A systematic error, however, that increased as the goniometer was rotated 45 degrees away from the cameras was evident. In experiment 2, a robotic arm was fitted with four IREDs and made to repeat a defined movement trajectory 10 times at each of three spatial locations. The ICCs for portions of each trajectory ranged from .20 to .99. The results show that reliable and valid results can be obtained from this motion analysis system if adequate precautions are taken to reduce unwanted light reflections. Reliability and validity decreased somewhat as the object was rotated further away from the plane in which the cameras were mounted.