Stratified multisystem predictors of gait stability in older adults

Gait stability arises from interactions between physiological, cognitive, and psychological systems - yet these domains are often assessed in isolation. This study investigated how these domains collectively influence gait stability in 340 community-dwelling older adults. Participants completed the Physiological Profile Assessment (PPA), cognitive, and fear-of-falling evaluations along with a gait assessment during preferred and fast speeds. Gait stability was quantified as the anteroposterior Margin of Stability (MoSAP). Participants were stratified into four PPA-based fall-risk groups: low, mild, moderate, and high risk. Univariate and multivariate regression analyses within each group, including principal component analysis, identified domain specific predictors of MoSAP. MoSAP varied across fall-risk groups and walking speeds, indicating sensorimotor influences on dynamic stability regulation. At preferred walking speed, key predictors were physiological–cognitive factors (low risk), postural sway (mild risk), strength and balance (moderate risk), and physiological–cognitive interactions (high risk). At fast walking speed, key predictors were cognitive factors (low risk), strength and balance (moderate risk), and no single predictor emerged in high risk. Fear-of-falling interactions emerged only at fast walking speed in mild and moderate fall risk groups. MoSAP varied systematically with fall-risk and task demand, supporting distinct multisystem control strategies and need for stratified, integrated assessment across domains.