Detection of Gait Intention with an Insole Device

Anticipatory postural adjustments (APAs) refer to the phenomenon in which the human body contracts muscles to minimize postural disturbances and maintain balance before performing a certain action. The purpose of this study was to investigate whether insole devices are capable of detecting walking intentions using APAs. Five healthy subjects participated in the walk test. Ground reaction force (GRF) and center of pressure (COP) were evaluated with an insole device. Electromyography (EMG) sensors and motion capture system was used to capture muscle response and to determine the reference point for the start of walking. And Insole device was evaluated comparing the times of APA occurrence during walking with EMG sensors, and analyzing the consistency of the data. The EMG signal was found to be faster than that of the insole device. Moreover, changes in the signals from both sensors earlier than the movement of the knee on the swing leg side. However, EMG signal showed lower consistency than insole device. Therefore, it is possible to determine the gait intention of a wearer using GRF measured through the insole device rather than using EMG for which signal acquisition is difficult. It is expected that the determined gait intention could be used as a reference time point to create the trigger signal required for control of a walking assistive device.