The Discriminant Value of Phase-Dependent Local Dynamic Stability of Daily Life Walking in Older Adult Community-Dwelling Fallers and Nonfallers
(a) A schematic representation of the reaction distance based on trajectories within a small neighborhood (gray circle) of the state space. The initial average perturbation distance was computed from multiple distances (t) within the neighborhood. Note that the left panel illustrates a 3D state space reconstruction where the computations of are based on a 6D state space reconstruction. (b) A representative example of a log-reaction curve normalized to the step cycle for a faller (red) and a nonfaller (blue) for initial perturbation at 0% of the step cycle. (c) The same example of a log-reaction curve for initial perturbation at 60% of the step cycle. The slopes of the regression lines for the initial 10% (black lines in shaded areas of (a) and (b)) were defined as the local dynamic stability according to (1).