Age-related changes in large muscle group movements during sleep

This study aims to investigate large muscle group movements (LMM) during sleep across the lifespan, from school-aged children to older adults, and to examine their relationship with sleep architecture (REM and NREM). A total of 141 healthy participants were included, divided into five age groups: school-aged children (n = 43), adolescents (n = 31), young adults (n = 27), adults (n = 16), and older adults (n = 24). Polysomnography (PSG) was used to record sleep data and LMM, along with LMM associated with arousals (LMMA) and awakenings (LMMW), were scored according to recently established criteria. The LMM indices and durations were analysed for each group, and statistical comparisons were made between age groups and across REM and NREM sleep. LMM indices significantly increased with age, with older adults exhibiting the highest frequency of LMM, LMMA, and LMMW. The LMM duration was longer in younger participants and shorter in older adults. Significant differences in LMM patterns between REM and NREM sleep were observed, particularly in adults and older adults, where LMM and LMMA were more prevalent in REM sleep. No significant sex differences were found across age groups. LMM during sleep showed clear age-related trends, increasing in frequency and decreasing in duration with advancing age. These movements are more prevalent during REM sleep in older adults, reflecting age-related sleep fragmentation and instability. The findings provide important normative data for LMM across the lifespan and demonstrate that sleep-related motor activity is closely linked to changes in sleep architecture.