Background:

Recently, the successor of the Conventional Gait Model, the CGM2 was introduced. Even though achievable reliability of gait kinematics is a well-assessed topic in gait analysis for several models, information about reliability in difficult study samples with high amount of subcutaneous fat is scarce and to date, not available for the CGM2. Therefore, this study evaluated the test–retest reliability of the CGM2 model for difficult data with high amount of soft tissue artifacts.

Research question:

What is the test–retest reliability of the CGM2 during level walking and stair climbing in a young obese population? Is there a clinically relevant difference in reliability between a standard direct kinematic model and the CGM2?

Methods:

A retrospective test–retest dataset from eight male and two female volunteers was used. It comprised standard 3D gait analysis data of three walking conditions: level walking, stair ascent and descent. To quantify test–retest reliability the Standard Error of Measurement (SEM) was calculated for each kinematic waveform for a direct kinematic model (Cleveland clinic marker set) and the CGM2.

Results:

Both models showed an acceptable level of test–retest reliability in all three walking conditions. However, SEM ranged between two and five degrees (${}^{\circ }$) for both models and, thus, needs consideration during interpretation. The choice of model did not affect reliability considerably. Differences in SEM between stair climbing and level walking were small and not clinically relevant ($<$1°).

Significance:

Results showed an acceptable level of reliability and only small differences between the models. It is noteworthy, that the SEM was increased during the first half of swing in all walking conditions. This might be attributed to increased variability resulting for example from inaccurate knee and ankle axis definitions or increased variability in the gait pattern and needs to be considered during data interpretation.

中文翻译：

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使用标准运动学和CGM2模型在年轻肥胖人群中行走和爬楼梯运动学的可靠性

背景：

最近，引入了传统步态模型CGM2的后继者。尽管在几个模型的步态分析中，可以实现的步态运动学可靠性已经得到了很好的评估，但是关于困难的研究样本中皮下脂肪含量高的研究，关于可靠性的信息仍然很少，而且迄今为止，CGM2还不可用。因此，本研究评估了CGM2模型对于具有大量软组织伪影的困难数据的重测可靠性。

研究问题：

在年轻的肥胖人群中，水平行走和爬楼梯期间CGM2的重测可靠性如何？标准直接运动学模型和CGM2之间在临床上是否存在可靠性相关的差异？

方法：

使用来自八名男性和两名女性志愿者的回顾性测验-再测数据集。它包括三种步行条件的标准3D步态分析数据：水平步行，楼梯上升和下降。为了量化重测的可靠性，针对直接运动学模型（克利夫兰临床标记集）和CGM2，为每个运动学波形计算了标准测量误差（SEM）。

结果：

在所有三种步行条件下，两个模型均显示出可接受的重测可靠性水平。但是，SEM的范围在2到5度之间（${}^{\circ }$），因此在解释时需要考虑。型号的选择不会显着影响可靠性。爬楼梯和水平行走之间的SEM差异很小，并且在临床上不相关（$<$1°）。

意义：

结果显示出可接受的可靠性水平，并且模型之间的差异很小。值得注意的是，在所有步行条件下，上半身的SEM在增加。这可能归因于可变性的增加（例如，膝盖和脚踝轴定义不正确）或步态模式的可变性增加，需要在数据解释期间予以考虑。