Time-of-Day Effects on Postural Balance in Blind Children: A Cross-Sectional Comparative Study

The effect of time-of-day on postural balance has been documented in sighted children. Given that vision is central to postural control and circadian synchronization, its absence may influence these temporal patterns. To date, the time-of-day effect on postural balance in blind children remains unexamined. Therefore, this study aimed to assess the effect of time-of-day on postural balance in blind children and to examine whether its temporal variation differs from the typical daily pattern observed in sighted peers.

Two groups participated: 12 blind and 12 age-matched sighted children. Postural balance was assessed using the center of pressure mean velocity (CoP_Vm) during bipedal stance on firm and foam surfaces at 07:00, 12:00, 17:00, and 22:00 h. Quadriceps femoris muscle strength, auditory reaction time (ART), and oral temperature were also evaluated at each time point.

Blind children showed a significant nocturnal decrease in CoP_Vm at 22:00 h (p < 0.001), temporally aligned with a significant increase in lower limb strength (p < 0.001). Oral temperature was significantly lower at 07:00 h (p < 0.001), whereas no significant time-of-day effect was observed on ART (p > 0.99). In sighted children, at 17:00 h, CoP_Vm was significantly lower (p < 0.001), ART decreased significantly (p < 0.001), MVC increased significantly (p < 0.001), and oral temperature showed a significant peak (p < 0.001).

Time-of-day influences postural balance in blind children, but with atypical fluctuations compared to sighted peers. Postural stability was lower during the diurnal phase in blind participants, highlighting the need for caution during balance-demanding daily activities to reduce fall-related injury risk.