Abstract
OBJECTIVE: Standing postural instability is associated with age-related functional decline and risk of fall. This study investigated the ability to control posture during stationary standing in young adults, older adults, and at-risk older adults from the perspective of postural sway and cumulative lower limb angles. METHODS: The participants were instructed to assume a stationary upright position in three conditions: unstable, stable, and unstable with executive function tasks. Postural control was quantitatively assessed using a center-of-gravity sway meter and angular velocity sensors. RESULTS: The 58 participants (all female participants) included in this study were divided into groups of young adults (n = 21), older adults (n = 25), and at-risk older adults (n = 12). Compared with younger adults, older adults and at-risk older adults showed decreased executive function and increased total pressure swing length under unstable conditions. The cumulative angles of the ankle joints also increased. Similar results were observed under unstable and attention-dispersal conditions. Additionally, older adults and at-risk older adults showed increased cumulative knee and hip angles. CONCLUSION: Older adults and at-risk older adults experience postural instability and use different postural control strategies compared with younger individuals under unstable or unstable conditions with attention dispersion.