Sleep has been shown to enhance simple motor skill learning “offline” in young adults. “Offline learning” refers to either the stabilization or the enhancement of a memory through the passage of time without additional practice. It is still not clear whether a functional motor task will benefit from sleep to produce offline motor skill enhancement. Physical therapists frequently teach clients functional motor skills; therefore, it is important to understand how sleep affects learning of these skills. The goal of this study was to establish whether sleep enhances the learning of a functional motor task. A prospective, cross-sectional, repeated-measures design was used. Young, healthy participants (N=24) were assigned at random to either a sleep group or a no-sleep group. The sleep group practiced a novel walking task in the evening and underwent retention testing the following morning, and the no-sleep group practiced the task in the morning and underwent retention testing in the evening. Outcome measures included time around the walking path and spatiotemporal gait parameters. Only participants who slept after practicing the novel walking task demonstrated a significant offline improvement in performance. Compared with the no-sleep group, participants in the sleep group demonstrated a significant reduction in the time around the walking path, an increase in tandem velocity, an increase in tandem step length, and a reduction in tandem step time. Time-of-day effect and inability to ensure a certain amount of sleep quantity and quality of participants were limitations of the study.
This study was the first to offer evidence that sleep facilitates learning clinically relevant functional motor tasks. Sleep is a significant factor that physical therapists should take into account when teaching clients motor skills.