Authors:	Horst, Fabian Eekhoff, Alexander Newell, Karl M. Schöllhorn, Wolfgang I.
Title:	Intra-individual gait patterns across different time-scales as revealed by means of a supervised learning model using kernel-based discriminant regression
Online publication date:	15-Jun-2022
Year of first publication:	2017
Language:	english
Abstract:	Objective Traditionally, gait analysis has been centered on the idea of average behavior and normality. On one hand, clinical diagnoses and therapeutic interventions typically assume that average gait patterns remain constant over time. On the other hand, it is well known that all our movements are accompanied by a certain amount of variability, which does not allow us to make two identical steps. The purpose of this study was to examine changes in the intra-individual gait patterns across different time-scales (i.e., tens-of-mins, tens-of-hours). Methods Nine healthy subjects performed 15 gait trials at a self-selected speed on 6 sessions within one day (duration between two subsequent sessions from 10 to 90 mins). For each trial, time-continuous ground reaction forces and lower body joint angles were measured. A supervised learning model using a kernel-based discriminant regression was applied for classifying sessions within individual gait patterns. Results and discussion Discernable characteristics of intra-individual gait patterns could be distinguished between repeated sessions by classification rates of 67.8 ± 8.8% and 86.3 ± 7.9% for the six-session-classification of ground reaction forces and lower body joint angles, respectively. Furthermore, the one-on-one-classification showed that increasing classification rates go along with increasing time durations between two sessions and indicate that changes of gait patterns appear at different time-scales. Conclusion Discernable characteristics between repeated sessions indicate continuous intrinsic changes in intra-individual gait patterns and suggest a predominant role of deterministic processes in human motor control and learning. Natural changes of gait patterns without any externally induced injury or intervention may reflect continuous adaptations of the motor system over several time-scales. Accordingly, the modelling of walking by means of average gait patterns that are assumed to be near constant over time needs to be reconsidered in the context of these findings, especially towards more individualized and situational diagnoses and therapy.
DDC:	610 Medizin 610 Medical sciences 796 Sport 796 Athletic and outdoor sports and games
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 02 Sozialwiss., Medien u. Sport
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-7155
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	PLoS one 12 6
Pages or article number:	e0179738
Publisher:	PLoS
Publisher place:	Lawrence, Kan.
Issue date:	2017
ISSN:	1932-6203
Publisher URL:	http://dx.doi.org/10.1371/journal.pone.0179738
Publisher DOI:	10.1371/journal.pone.0179738
Appears in collections:	DFG-OA-Publizieren (2012 - 2017)