Postural Instability after Stepping on a Stair in Older Adults: A Pilot Study

Abstract

This study aimed to examine how older adults (OA) control their postural stability after stepping on a stair in comparison to young adults (YA). Ten OA and 10 YA participated in this study. Participants ascended a single stair (15 cm high by 30 cm wide) which was secured atop one of the force plates. Ground reaction forces (GRFs) and center of pressure (COP) motion data were obtained from the force plate under the stair. After standing on the stair with both feet, GRFs and COP data for a 3 s duration were analyzed to assess postural variables, including time to stabilization (TTS), COP velocity (COPVEL), and COP sway area (COPSWAY). A significant difference in TTS in the anterior–posterior direction between OA and YA (p = 0.032) was observed, indicating that OA had difficulty stabilizing their body posture after the stair ascent compared to YA. For COP postural variables, no significant differences in COPVEL (p = 0.455) and COPSWAY (p = 0.176) were observed between OA and YA. Study findings indicate that older adults have less capacity to regain postural stability compared to young adults following a challenging dynamic movement.

Keywords

• postural stability
• older adults
• stepping on a stair
• time to stabilization