The Dynamic Gait Index Does Not Sufficiently Capture the Ability to Adapt Walking Under Dual-Task Conditions

Walking in daily life requires the performance of multiple tasks simultaneously, such as walking and talking. Thus, dual-task performance is critical in assessments of functional gait and mobility. The Dynamic Gait Index (DGI) is used widely to evaluate walking capacity, but its ability to capture changes in walking function while under cognitive load is unclear. In this study, we examined whether DGI scores are associated with the dual-task cost (DTC) of walking performance in adults (aged 41 [19]) across a spectrum of walking abilities. Participants completed treadmill walking trials under single- and dual-task (visual-verbal Stroop) conditions. Significant dual-task effects were found across all primary walking measures, including step length, step width, double support time, and trailing limb angle, with large interindividual variability. Correlations between DGI score and DTC were not observed. These findings suggest that DGI and DTC capture different aspects of walking function. While the DGI may be useful for identifying gross impairments, DTC is more sensitive to subtle changes in walking function. Integrating dual-task assessments into existing evaluations of walking function may mobility screening, particularly in aging and preclinical populations.