Accuracy of digitization using automated and manual methods
Accuracy of digitization using automated and manual methods
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DOI：
10.1093/ptj/79.6.558
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发表时间：
1999-06-01
期刊：
影响因子：
3.2
通讯作者：
Voelz, JT
中科院分区：
文献类型：
--
作者：
Wilson, DJ;Smith, BK;Voelz, JT
背景和目的。对人体运动感兴趣的人会使用计算机化的 3 维 (3-D) 运动测量系统。本研究的目的是 (1) 确定在不同速度的摆动运动过程中确定段间角度的准确度限制，以及 (2) 确定自动数字化和经验丰富的手动评分员数字化带来的准确度变化。方法。通过从 4 个角度（0 度[无运动]、45 度、90 度和 120 度）释放摆，系统地增加了 T 形摆的角速度。根据放置在摆锤上的标记计算出的 12 个参考角度在每个释放位置进行 10 次试验，在 20 帧上进行估计。结果。通过 3D 运动测量系统重建的段间角度的试验和帧的平均误差在所有释放位置上都在 +/-1 度以内。方差分析和事后 Tukey 检验表明，自动数字化试验的平均误差大于手动数字化试验的平均误差。对于自动数字化试验，静态试验（释放位置 = 0 度）产生的平均误差比产生运动的试验要小。所有评分者的 ICC 表现出高度的一致性，范围为 0.707 至 0.999。结论与讨论。我们的研究结果支持这样的结论：在严格控制的条件下，3D 运动测量系统可以在一系列角速度范围内产生临床上可接受的精度测量结果。此外，无论数字化方法如何，可接受的精度都是可能的。
Background and Purpose. Computerized 3-dimensional (3-D) motion measurement systems are used by those interested in human motion. The purposes of this study were (1) to determine the limits of accuracy in determining intersegmental angles during pendular motion at varying speeds and (2) to determine changes in accuracy introduced by autodigitization and digitization by experienced manual raters. Methods. Angular speed of a T-shaped pendulum was systematically increased by releasing the pendulum from 4 angles (0 degrees [no movement], 45 degrees, 90 degrees, and 120 degrees). Twelve reference angles calculated from markers placed on the pendulum were estimated over 20 frames for 10 trials at each release position. Results. Mean errors across trials and frames for intersegmental angles reconstructed by a 3-D motion measurement system were within +/-1 degree across all release positions. An analysis of variance and a Post hoc Tukey test revealed that the mean error for the autodigitized trials was larger than that for the manually digitized trials. For the autodigitized trials, the static trials (release position =0 degrees) produced less mean error than the trials with movement produced. The ICCs showed a high degree of consistency among all raters, ranging from .707 to .999. Conclusion and Discussion. Our findings support the conclusion that under carefully controlled conditions, a 3-D motion measurement system can produce clinically acceptable measurements of accuracy across a range of angular speeds. Furthermore, acceptable accuracy is possible regardless of the digitization method.