PURPOSE: The aim of this study was to compare gait stability and variability between walking conditions and age groups. METHODS: Twenty-six healthy younger and older females participated. Trunk acceleration in the vertical (V), medial-lateral (ML) and anteriorposterior (AP) directions during 5 minutes walking overground and 3 minutes walking on the treadmill at self-selected speed were recorded. Root mean square and standard deviations of acceleration, stride time and its variability, Lyapunov exponents (LE), multiscale entropy (MSE) and harmonic ratios (HR) were computed. RESULTS: Both age groups showed significantly higher stride time variability and short-term LE in all directions during overground walking. For the older group, overground walking showed higher V and AP standard deviation. Significantly lower values for overground walking were observed for long-term LE (V and ML for the younger group, ML for the older group), HR (ML for the older group) and MSE (V for the older group). Significant age-related differences were found for V long-term LE for overground walking. CONCLUSIONS: The present findings suggest that both linear and advanced computational techniques for gait stability and variability assessment in older adults are sensitive to walking conditions.

Institute of Normal and Pathological Physiology Slovak Academy of Sciences Bratislava Slovakia

Palacky University Olomouc Faculty of Physical Culture Department of Natural Sciences in Kinanthropology Olomouc Czech Republic

University Grenoble Alpes EA AGEIS Grenoble France French University Institute Paris France