Relationship between gait stability indices and gait parameters comprising joint angles based on walking data from 288 people

Stability during walking is essential because falling accidents may lead to severe injuries. In this study, we calculated the margin of stability (MoS) and the maximum Lyapunov exponent (λ(s)), which are two major stability indices for walking, using a gait database representing 300 healthy people. Previously, the relationships between these indices and other gait parameters, including joint angles, have not been investigated in such a large subject pool. Therefore, we determined the relationships between these stability indices and the gait parameters by calculating correlation coefficients and performing multiple regression analysis. The results indicated that MoS is dominated by walking speed in the forward direction and associated with various joint angles in the lateral direction. Conversely, no relationships were identified between λ(s) and the gait parameters. Although both MoS and λ(s) are considered as measures of gait stability, they are independent. The results of this study suggest that MoS and λ(s) represent different aspects of gait motion.