Effects of cognitive-motor interference during walking: A meta-analysis on healthy individuals

The impact of simultaneously performing two tasks, and its potentially detrimental effect, have been extensively investigated. Carrying out two tasks might require more resources than performing them in isolation, resulting in worsened performance for either or both tasks. Growing evidence from dual-task paradigms highlights considerable advancements in experimental designs, which, however, reflect in a variety of distinct parameters to assess cognitive-motor interference (CMI). Such heterogeneity hampers comparing results from single studies, and thus the identification of the most suitable paradigms to assess CMI in experimental and clinical settings. To address this issue, we performed a meta-analysis of published studies addressing CMI during overground walking in healthy participants. We aimed to assess the direction and strength of CMI and the impact of different cognitive tasks on gait performance. We retrieved twenty-five studies that allowed performing five distinct meta-analyses focusing on spatial, temporal and spatiotemporal gait measures, alongside cognitive performance. We additionally performed moderator analyses considering age and type of cognitive task. The results confirmed an overall CMI effect on gait measures, as well as on task accuracy, but not on reaction times. Moderator analyses highlighted significant results for gait speed, while no effect of age group was found. Overall, these results reflect the considerable heterogeneity of measurements and tasks employed to assess CMI and its modulating factors. Future research in this field should therefore promote the use of more standardized paradigms, both in healthy participants and clinical populations, particularly when aiming at developing targeted interventions such as training for neuro-motor rehabilitation.