System for Measuring the Walking Speed of a Human Subject on a Force Plate

This paper presents the development of a system for measuring the walking speed on a force plate that measures ground reaction. The walking speed measurement system must meet the following criteria: minimal impact on the force plate, easy installation/dismantling, speed must be detected "without contact" and speed of subject must be detected irrespective of the subject's clothing colour, it must provide the possibility of using several types of force plate, it must allow the addition of new functions and have a competitive price. Ground reaction force was measured using the AMTI's AccuGait force plate and the NetForce component, while analysis was performed using the BioAnalysis module. To assess the three components of the ground reaction force provided by the force plate, for a subject not wearing shoes, walking at different speeds, two measurement sessions were organized: placing optical barriers of the walking speed measurement system at distances of 2.5 m and 0.7 m, respectively. Upon analyzing the values obtained in this case study, we can observe an increase in values of the following components: vertical component, Fz, medio-lateral component, Fy and anterior-posterior component, Fx at the speed of 2.33 m/s, compared to those obtained at 0.6 m/s. By comparing values provided by the force plate with optical barriers of the walking speed measurement system placed at distances of 2.5 m and 0.7 m, respectively, very small differences can be noticed. Therefore, the position of optical barriers does not affect the measurement of ground reaction force components.