title: Age effects on the control of dynamic balance during step adjustments under temporal constraints.
abstract: This study investigated the age effects on the control of dynamic balance during step adjustments under temporal constraints. Fifteen young adults and 14 older adults avoided a virtual white planar obstacle by lengthening or shortening their steps under free or constrained conditions. In the anterior-posterior direction, older adults demonstrated significantly decreased center of mass velocity at the swing foot contact under temporal constraints. Additionally, the distances between the 'extrapolated center of mass' position and base of support at the swing foot contact were greater in older adults than young adults. In the mediolateral direction, center of mass displacement was significantly increased in older adults compared with young adults. Consequently, older adults showed a significantly increased step width at the swing foot contact in the constraint condition. Overall, these data suggest that older adults demonstrate a conservative strategy to maintain anterior-posterior stability. By contrast, although older adults are able to modulate their step width to maintain mediolateral dynamic balance, age-related changes in mediolateral balance control under temporal constraints may increase the risk of falls in the lateral direction during obstacle negotiation.
authors: Department of Physical Therapy, Faculty of Health Sciences, Tsukuba International University, Ibaraki, Japan. Electronic address: w-nakano@tius.ac.jp.
authors: Wataru
authors: W
authors: Nakano
authors: Department of Physical Therapy, Faculty of Health Sciences, Tsukuba International University, Ibaraki, Japan.
authors: Takashi
authors: T
authors: Fukaya
authors: Department of Physical Therapy, Faculty of Health Sciences, Tsukuba International University, Ibaraki, Japan.
authors: Satomi
authors: S
authors: Kobayashi
authors: Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan.
authors: Yukari
authors: Y
authors: Ohashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005260:Female; D005528:Foot / Q000502:physiology; D005684:Gait; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D055815:Young Adult
keywords: Dynamic balance; Obstacle negotiation; Older adults; Step adjustment; Temporal constraints