Article

To establish a supportive technology for reducing the risk of falling in older
people, it is essential to clarify gait characteristics in elderly individuals
that are possibly linked to the risk of falling during actual daily activities.
In this study, we developed a system to monitor human gait in an outdoor
environment using an inertial measurement unit consisting of a tri-axial
accelerometer and tri-axial gyroscope. Step-by-step foot trajectories were
estimated from the sensor unit attached to the dorsum of the foot. Specifically,
stride length and foot clearance were calculated by integrating the
gravity-compensated translational acceleration over time during the swing phase.
Zero vertical velocity and displacement corrections were applied to obtain the
final trajectory, assuming the slope of the walking surface is negligible. Short,
normal, and long stride-length walking of 10 healthy participants was
simultaneously measured using the proposed system and a conventional motion
capture system to evaluate the accuracy of the estimated foot trajectory. Mean
accuracy and precision were approximately 20 +/- 50 mm, for stride length, and 2
+/- 7 mm for foot clearance, indicating that the swing phase trajectory of the
sensor unit attached to the foot was reconstructed more accurately and precisely
using the proposed system than with previously published methods owing to the
flat floor assumption. Although some methodological limitations certainly apply,
this system will serve as a useful tool to monitor human walking during daily activities.
CI - Copyright (c) 2016 Elsevier B.V. All rights reserved.

Langue : ANGLAIS