Identification of multiple U-turns using IMUs: Comparative assessment of three methods

Daily life locomotion includes sequences of straight and turn walking bouts. Wearable inertial measurement units (IMU) allow to extend the traditional gait analysis to tasks including turns. In this context, the preliminary goal of any IMU-based methodology is the identification of turns, thus allowing the trial segmentation into straight and turn bouts. Various methods have been proposed to identify turns in walking trials with a known number of turns. The aim of this study was to verify the applicability of three published methods to gait trials with an unknown number of turns, and to patients with different kinds of pathologies affecting gait. Results show that none of the methods was 100% accurate in detecting turns.