Article

Time periods composing stance phase of gait can be clinically meaningful
parameters to reveal differences between normal and pathological gait. This study
aimed, first, to describe a novel method for detecting stance and inner-stance
temporal events based on foot-worn inertial sensors; second, to extract and validate relevant metrics from those events; and third, to investigate their
suitability as clinical outcome for gait evaluations.
42 subjects including
healthy subjects and patients before and after surgical treatments for ankle
osteoarthritis performed 50-m walking trials while wearing foot-worn inertial
sensors and pressure insoles as a reference system. Several hypotheses were
evaluated to detect heel-strike, toe-strike, heel-off, and toe-off based on
kinematic features. Detected events were compared with the reference system on
3193 gait cycles and showed good accuracy and precision. Absolute and relative
stance periods, namely loading response, foot-flat, and push-off were then
estimated, validated, and compared statistically between populations. Besides
significant differences observed in stance duration, the analysis revealed
differing tendencies with notably a shorter foot-flat in healthy subjects. The
result indicated which features in inertial sensors' signals should be preferred
for detecting precisely and accurately temporal events against a reference
standard. The system is suitable for clinical evaluations and provides temporal
analysis of gait beyond the common swing/stance decomposition, through a
quantitative estimation of inner-stance phases such as foot-flat.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS