Older adult frontal plane balance during 90 degree turns while walking.

This study examined how older adults regulated their balance during turns relevant to everyday mobility, towards informing future fall-risk mitigation approaches. Sixteen healthy older adults participated in this study. Balance biomechanics were quantified using whole-body optical motion capture. Three tasks were performed 10-14 times: straight line gait, 90˚ pre-planned left turns, and 90˚ late-cued left turns that were cued visually. Frontal plane angular momentum ranges and the minimum horizontal distance between the center of mass and lateral edge of the base of support (lateral distance) were compared across tasks using linear mixed models. Lateral distance minima were larger during straight-line gait than either turning task, and larger during late-cued than pre-planned turns. Group-level analysis showed that frontal plane angular momentum ranges were smaller during straight-line gait than during either turn task. Participant-specific analyses revealed that not all participants followed the group-level statistical findings for angular momentum, with some demonstrating the opposite behavior. To explore these diverse balance behaviors, preliminary explorations found significant associations between balance state extrema and baseline assessment scores (e.g., greater concern about falling was associated with smaller angular momentum ranges). Additionally, this study prompts more thoughtful interpretations of balance biomechanics when attempting to characterize an individual's fall-risk.