Authors:
Mohamed Boutaayamou
1
;
2
;
Sophie Gillain
3
;
Cédric Schwartz
1
;
Vincent Denoël
1
;
Jean Petermans
3
;
Jean-Louis Croisier
1
;
Bénédicte Forthomme
1
;
Jacques G. Verly
2
;
Olivier Brüls
1
and
Gaëtan Garraux
2
Affiliations:
1
University of Liège (ULiège), Belgium
;
2
ULiège, Belgium
;
3
University Hospital Center of Liège, Belgium
Keyword(s):
Validated Extraction, Refined Gait Parameters, Gait Sub-Phase Durations, Foot-Worn Accelerometers, Older Adults, Signal Processing.
Abstract:
Validated extraction of gait sub-phase durations using an ambulatory accelerometer-based system is a current unmet need to quantify subtle changes during the walking of older adults. In this paper, we describe (1) a signal processing algorithm to automatically extract not only durations of stride, stance, swing, and double support phases, but also durations of sub-phases that refine the stance and swing phases from foot-worn accelerometer signals in comfortable walking of older adults, and (2) the validation of this extraction using reference data provided by a gold standard system. The results show that we achieve a high agreement between our method and the reference method in the extraction of (1) the temporal gait events involved in the estimation of the phase/sub-phase durations, namely heel strike (HS), toe strike (TS), toe-off (TO), maximum of heel clearance (MHC), and maximum of toe clearance (MTC), with an accuracy and precision that range from ‒3.6 ms to 4.0 ms, and 6.5 ms t
o 12.0 ms, respectively, and (2) the gait phase/sub-phase durations, namely stride, stance, swing, double support phases, and HS to TS, TO to MHC, MHC to MTC, and MTC to HS sub-phases, with an accuracy and precision that range from ‒4 ms to 5 ms, and 9 ms to 15 ms, respectively, in comfortable walking of a thirty-eight older adults ( (mean ± standard deviation) 71.0 ± 4.1 years old). This demonstrates that the developed accelerometer-based algorithm can extract validated temporal gait events and phase/sub-phase durations, in comfortable walking of older adults, with a promising degree of accuracy/precision compared to reference data, warranting further studies.
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