Time-of-day influences postural balance in older adults

Area of Science:

• Gerontology
• Human Physiology
• Biomechanical Analysis

Background:

• Daily physiological and physical performance vary significantly over a 24-hour period due to circadian rhythms.
• The impact of time-of-day on postural balance in older adults remains largely unexamined.
• Understanding these diurnal variations is crucial for accurate clinical and research assessments.

Purpose of the Study:

• To investigate the influence of time-of-day on postural balance in an older adult population.
• To determine if specific diurnal patterns affect balance metrics in seniors.
• To provide data for optimizing the timing of balance assessments in older adults.

Main Methods:

• Utilized force plate analysis to measure center of pressure (CoP) excursion in 34 older adults.
• Measurements were conducted during a 30-second narrow, quiet, bilateral stance.
• Postural balance was assessed at three time points: approximately 9 a.m., 12:30 p.m., and 4 p.m. on the same day.

Main Results:

• Significant time-of-day effects were observed across all measured postural balance parameters (velocity-moment, confidence ellipse area, total sway area, total sway length) between 9 a.m. and 4 p.m. (p < 0.05).
• Balance decrements were most pronounced from midday (12:30 p.m.) to the afternoon (4 p.m.), with notable increases in sway parameters.
• No significant differences in sway parameters were detected between morning (9 a.m.) and midday (12:30 p.m.) assessments.

Conclusions:

• Time-of-day significantly influences postural balance in older adults.
• These findings highlight the importance of controlling for time-of-day in the assessment of postural balance in this demographic.
• Standardizing assessment timing is recommended for improved scientific and clinical relevance.