Application of the Gait Deviation Index to Study Gait Impairment in Adult Population With Spinal Cord Injury: Comparison With the Walking Index for Spinal Cord Injury Levels

Abstract

The Gait Deviation Index (GDI) is a multivariate measure of overall gait pathology based on 15 gait features derived from three-dimensional (3D) kinematic data. GDI aims at providing a comprehensive, easy to interpret, and clinically meaningful metric of overall gait function. It has been used as an outcome measure to study gait in several conditions: cerebral palsy (CP), post-stroke hemiparetic gait, Duchenne muscular dystrophy, and Parkinson’s disease, among others. Nevertheless, its use in population with Spinal Cord Injury (SCI) has not been studied yet. The aim of the present study was to investigate the applicability of the GDI to SCI through the assessment of the relationship of the GDI with the Walking Index for Spinal Cord Injury (WISCI) II. 3D gait kinematics of 34 patients with incomplete SCI (iSCI) was obtained. Besides, 3D gait kinematics of a sample of 50 healthy volunteers (HV) was also gathered with Codamotion motion capture system. A total of 302 (iSCI) and 446 (HV) strides were collected. GDI was calculated for each stride and grouped for each WISCI II level. HV data were analyzed as an additional set. Normal distribution for each group was assessed with Kolmogorov-Smirnov tests. Afterward, ANOVA tests were performed between each pair of WISCI II levels to identify differences among groups (p < 0.05). The results showed that the GDI was normally distributed across all WISCI II levels in both iSCI and HV groups. Furthermore, our results showed an increasing relationship between the GDI values and WISCI II levels in subjects with iSCI, but only discriminative in WISCI II levels 13, 19, and 20. The index successfully distinguished HV group from all the individuals with iSCI. Findings of this study indicated that the GDI is not an appropriate multivariate walking metric to represent the deviation of gait pattern in adult population with iSCI from a normal gait profile when it is compared with the levels of walking impairment described by the WISCI II. Future work should aim at defining and validating an overall gait index derived from 3D kinematic gait variables appropriate for SCI, additionally taking into account other walking ability outcome measures.

Derivation of the Gait Deviation Index for Spinal Cord Injury

“…In other respects, the comparison between the SCI-GDI and the WISCI II scale showed the stratification expected in levels 13 to 20 and in the control group, except in level 18 (see Figure 3 ), similarly to the results obtained when using the GDI ( Sinovas-Alonso et al, 2022 ). Nevertheless, an important difference is that only in the SCI-GDI, levels 15 and 16 showed a statistical difference, unlike in GDI (see Table 3 ).…”

“…Afterward, we calculated the SCI-GDI of the dataset using our basis and compared it with the WISCI II scale, to assess the stratification of gait impairment and discriminative properties of the new index (data analysis details in Section 2.4.2 ). To our knowledge, there is only one work published that studies the relationship of the GDI with a scale developed specifically for SCI and validated in this population, which is the WISCI II ( Sinovas-Alonso et al, 2022 ). We did not perform comparisons with other validated metrics in SCI, such as 10MWT, 6MWT, TUGT, or the BBS because these were not available.…”

“…To date, no studies have attempted to validate the GDI in SCI. To our knowledge, only two articles have investigated its application under this condition ( Hwang et al, 2021 ; Sinovas-Alonso et al, 2022 ). One of them uses the index to quantify and characterize gait patterns in ambulatory children and adolescents with transverse myelitis with respect to a normal gait pattern ( Hwang et al, 2021 ).…”

“…In this work, the difference in gait between patients and TD children was assessed with the GDI, without addressing the discriminative validity of the scale within different levels of impairment. The work presented in Sinovas-Alonso et al (2022 ) compared the GDI and the WISCI II, showing limited discriminative properties of the GDI in SCI because there were statistically significant differences in the GDI values only between levels 13, 19, 20, and the control group. Therefore, the applicability of the GDI to SCI population that leads to discriminate the heterogeneity of gait impairment is still an open question calling for investigation.…”

DataSheet1.xlsx

“…Numbers in parentheses indicate statistically significant differences found with an ANOVA (p < 0.05). The values marked with * indicate statistically significant differences found only in the SCI-GDI but not with the original GDI (Sinovas-Alonso,Herrera-Valenzuela, et al, 2022).…”