Herrera-Valenzuela Diana, Sinovas-Alonso Isabel, Moreno Juan C, Gil-Agudo Ángel, Del-Ama Antonio J
International Doctoral School, Rey Juan Carlos University, Madrid, Spain.
Biomechanics and Technical Aids Unit, National Hospital for Paraplegics, Toledo, Spain.
Front Bioeng Biotechnol. 2022 Jul 6;10:874074. doi: 10.3389/fbioe.2022.874074. eCollection 2022.
The Gait Deviation Index (GDI) is a dimensionless multivariate measure of overall gait pathology represented as a single score that indicates the gait deviation from a normal gait average. It is calculated using kinematic data recorded during a three-dimensional gait analysis and an orthonormal vectorial basis with 15 gait features that was originally obtained using singular value decomposition and feature analysis on a dataset of children with cerebral palsy. Ever since, it has been used as an outcome measure to study gait in several conditions, including spinal cord injury (SCI). Nevertheless, the validity of implementing the GDI in a population with SCI has not been studied yet. We investigate the application of these mathematical methods to derive a similar metric but with a dataset of adults with SCI (SCI-GDI). The new SCI-GDI is compared with the original GDI to evaluate their differences and assess the need for a specific GDI for SCI and with the WISCI II to evaluate its sensibility. Our findings show that a 21-feature basis is necessary to account for most of the variance in gait patterns in the SCI population and to provide high-quality reconstructions of the gait curves included in the dataset and in foreign data. Furthermore, using only the first 15 features of our SCI basis, the fidelity of the reconstructions obtained in our population is higher than that when using the basis of the original GDI. The results showed that the SCI-GDI discriminates most levels of the WISCI II scale, except for levels 12 and 18. Statistically significant differences were found between both indexes within each WISCI II level except for 12, 20, and the control group ( < 0.05). In all levels, the average GDI value was greater than the average SCI-GDI value, but the difference between both indexes is larger in data with greater impairment and it reduces progressively toward a normal gait pattern. In conclusion, the implementation of the original GDI in SCI may lead to overestimation of gait function, and our new SCI-GDI is more sensitive to larger gait impairment than the GDI. Further validation of the SCI-GDI with other scales validated in SCI is needed.
步态偏差指数（GDI）是一种无量纲的多变量测量指标，用于衡量整体步态病理状况，以单一分数表示，该分数表明与正常步态平均值的步态偏差。它是通过三维步态分析期间记录的运动学数据以及一个具有15个步态特征的正交向量基来计算的，该向量基最初是通过对脑瘫儿童数据集进行奇异值分解和特征分析获得的。从那时起，它就一直被用作研究多种情况下步态的结果指标，包括脊髓损伤（SCI）。然而，在脊髓损伤人群中应用GDI的有效性尚未得到研究。我们研究了这些数学方法的应用，以得出一个类似的指标，但使用的是脊髓损伤成人数据集（SCI - GDI）。将新的SCI - GDI与原始GDI进行比较，以评估它们的差异，并评估是否需要针对脊髓损伤的特定GDI，同时与WISCI II进行比较以评估其敏感性。我们的研究结果表明，需要一个包含21个特征的基来解释脊髓损伤人群步态模式中的大部分方差，并提供数据集中和外部数据中步态曲线的高质量重建。此外，仅使用我们的SCI基的前15个特征，在我们的人群中获得的重建保真度高于使用原始GDI基时的保真度。结果表明，SCI - GDI能够区分WISCI II量表的大多数水平，但不包括12级和18级。除了12、20级以及对照组外，在每个WISCI II水平内，两个指标之间均发现了统计学上的显著差异（<0.05）。在所有水平上，平均GDI值均大于平均SCI - GDI值，但在损伤程度较大的数据中，两个指标之间的差异更大，并且随着步态模式趋向于正常而逐渐减小。总之，在脊髓损伤中应用原始GDI可能会导致对步态功能的高估，并且我们新的SCI - GDI比GDI对更大的步态损伤更敏感。需要使用在脊髓损伤中得到验证的其他量表对SCI - GDI进行进一步验证。
