Day-to-day variation in sleep quality and static balance: results from an exploratory study

Sleep plays a critical role in promoting health and wellbeing. Variations in sleep quality and pattern may effect human balance. This study investigated whether day-to-day variations in sleep quality result in balance deteriorations during quiet standing. Ten healthy volunteers underwent sleep and balance assessment over two consecutive days. Sleep quality was assessed using sleep diaries, whereas balance was assessed in a gait laboratory to measure Center of Pressure (CoP) and Center of Mass (CoM) displacement. Results demonstrated an association among worsening in sleep quality and CoP displacement measures, both with eyes open and closed. The correlation coefficients between CoP and CoM also showed significant differences in subjects reporting a sleep worsening over the two days. These results suggest that short-term worsening in sleep quality may affect our balance and its associated mechanisms of control.