Identification of multiple U-turns using gyroscopes : comparative assessment of two methods

The identification of turnings segments during walking trials including the U-turns represents the first preliminary step required for the analysis of gait featuring straights and turns. To this purpose IMU-based methods were developed, however many of them rely on the a-priori knowledge of the number of turns. In this study, we selected two methods and compared them to evaluate their ability to detect the number of turns in continuous gait with multiple U-turns without further assumptions. Gyroscope data were recorded during gait trials performed at different speeds by two groups of subjects (healthy elderly and patients with Parkinson disease). Results show that the method that employs a sensor on the back yields better results than the one making use of a sensor on the ankles.