Automatic identification of gait events using an
instrumented sock

Preece, SJ; Kenney, LPJ; Major, M; Dias, T; Lay, E; Fernandes, B

Abstract

Background: textile-based transducers are an emerging technology in which piezo-resistive properties of materials
are used to measure an applied strain. By incorporating these sensors into a sock, this technology offers the
potential to detect critical events during the stance phase of the gait cycle. This could prove useful in several
applications, such as functional electrical stimulation (FES) systems to assist gait.
Methods: we investigated the output of a knitted resistive strain sensor during walking and sought to determine
the degree of similarity between the sensor output and the ankle angle in the sagittal plane. In addition, we
investigated whether it would be possible to predict three key gait events, heel strike, heel lift and toe off, with a
relatively straight-forward algorithm. This worked by predicting gait events to occur at fixed time offsets from
specific peaks in the sensor signal.
Results: our results showed that, for all subjects, the sensor output exhibited the same general characteristics as
the ankle joint angle. However, there were large between-subjects differences in the degree of similarity between
the two curves. Despite this variability, it was possible to accurately predict gait events using a simple algorithm.
This algorithm displayed high levels of trial-to-trial repeatability.
Conclusions: this study demonstrates the potential of using textile-based transducers in future devices that provide active gait assistance.

Citation

instrumented sock. Journal of NeuroEngineering and Rehabilitation, 8, 32. https://doi.org/10.1186/1743-0003-8-32

• Journal Article Type: Article
• Publication Date: May 1, 2011
• Deposit Date: Sep 28, 2011
• Publicly Available Date: Apr 5, 2016
• Journal: Journal of NeuroEngineering and Rehabilitation
• Print ISSN: 1743-0003
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Pages: 32
• DOI: https://doi.org/10.1186/1743-0003-8-32
• Publisher URL: http://dx.doi.org/ 10.1186/1743-0003-8-32