Age-Related Differences in Coupling of Toe and Center of Pressure during the One-Legged Stance

This study aimed to investigate the characteristics of the coupling of the center of pressure (COP) movement and toes in older adults during one-legged standing (OLS). Participants were community dwelling older and younger adults. Toe vertical force during the OLS was recorded using a plantar-pressure distribution system, and the vertical forces in the hallux, little toe, and the first and fifth metatarsophalangeal (MP) joints were analyzed. A cross-correlation function was performed to examine the coordination between toes and between COP movement and four regions of the foot. The cross-correlation functions showed no significant difference in coefficients between toes. The OLS duration in the older adults was significantly correlated with the coefficient between the medial-lateral component of the COP and the first MP region. This study suggests that it is important to press the first MP region appropriately relative to COP movement to maintain the OLS.