Process of dynamic balance recovery after voluntary perturbation: a time-series data analysis of young and older adults

• Published in: Journal of Physical Therapy Science Vol. 36; no. 9; pp. 481 - 487
• Main Authors: Kimura, Daisuke, Oku, Kosuke, Ogasawara, Issei, Ito, Tomotaka, Nakata, Ken
• Format: Journal Article
• Language: English
• Published: Japan The Society of Physical Therapy Science 01.01.2024; Japan Science and Technology Agency
• Subjects: Aging; Consecutive postural adjustments; Older people; Online adjustment; Original; Aging; Online adjustment; Consecutive postural adjustments
• ISSN: 0915-5287; 2187-5626
• DOI: 10.1589/jpts.36.481

[Purpose] This study investigated differences in the convergence mode of post-step sway between young and older adults using a step-down task to identify fall causes in older adults and assess consecutive postural adjustments. [Participants and Methods] This study included 15 young and 15 older adults (nine females and six males in each group). The participants stepped down from a standing position to a force platform 10 cm lower and maintained a one-leg standing position. The center-of-pressure total trajectory length was assessed using a force plate and regression equations for time and sway were derived from the associated time-series data for both groups. [Results] An inversely proportional aspect was observed for both groups, with significantly different coefficients and constants. The center-of-pressure total trajectory length per second from foot contact was significantly different between 2–3 s and 4–5 s in the older group but not in the younger group. [Conclusion] The results suggest a difference in the convergence mode of dynamic balance between the two groups, with young adults exhibiting a more rapid balance-sway reduction than older adults. The novel computational approach used in this study may be useful for dynamic balance measurements.