Effects of one night of sleep deprivation on single- and dual-task gait

Sleep deprivation impairs cognitive control, which may affect movements that rely on these processes, such as walking. To test whether gait changes after one night of sleep deprivation reflect reduced cognitive capacity, we compared its effects with those of dual-task walking (i.e., walking while performing a simultaneous cognitive task). We hypothesize that sleep deprivation will produce gait changes similar to those under dual-task conditions. Eighteen healthy adults (9 female, 9 male; 22.2 (2.3) yrs) were tested the morning after a sleep deprivation (SDEP) and a control night. Participants completed two 2-min trials: single-task walking and walking with a concurrent 2-back working memory task (DT, dual-task). Using lateral foot and pelvis marker trajectories, we calculated spatiotemporal parameters, foot placement error in antero-posterior (FPEAP) and mediolateral (FPEML) directions, and mediolateral margin of stability (MoSML). SDEP increased average step time (p<0.001) and step length (p=0.001), and DT reduced spatiotemporal variability. Both SDEP (p=0.001) and DT (p<0.001) reduced FPEAP, but only DT reduced FPEML (p<0.001). Additionally, mean MoSML decreased only in SDEP (p=0.011). Overall, these findings suggest that while sleep deprivation and dual-tasking both affect gait, the effects of sleep deprivation on gait cannot be fully explained by reduced cognitive resources.