Assessment of Walking Features From Foot Inertial Sensing

TLDR

The study develops an ambulatory monitoring system to estimate spatio‑temporal gait parameters. The system employs a foot‑mounted inertial measurement unit with an accelerometer and gyroscope, uses gait‑phase segmentation and strapdown integration to compute stride length, speed, and incline, and its accuracy was validated on healthy adults on a treadmill. Experiments show root‑mean‑square errors below 0.18 km/h for speed and 1.52 % for incline, indicating foot inertial sensing reliably identifies gait cycles and accurately estimates walking speed and incline.

Abstract

An ambulatory monitoring system is developed for the estimation of spatio-temporal gait parameters. The inertial measurement unit embedded in the system is composed of one biaxial accelerometer and one rate gyroscope, and it reconstructs the sagittal trajectory of a sensed point on the instep of the foot. A gait phase segmentation procedure is devised to determine temporal gait parameters, including stride time and relative stance; the procedure allows to define the time intervals needed for carrying an efficient implementation of the strapdown integration, which allows to estimate stride length, walking speed, and incline. The measurement accuracy of walking speed and inclines assessments is evaluated by experiments carried on adult healthy subjects walking on a motorized treadmill. Root-mean-square errors less than 0.18 km/h (speed) and 1.52% (incline) are obtained for tested speeds and inclines varying in the intervals [3, 6] km/h and [-5, + 15]%, respectively. Based on the results of these experiments, it is concluded that foot inertial sensing is a promising tool for the reliable identification of subsequent gait cycles and the accurate assessment of walking speed and incline.