Design and characterization of a mobile force plate and three-dimensional motion analysis system

In order to implement an unobstructed assessment of walking gait, we proposed a mobile force plate and three-dimensional motion analysis system (M3D) to measure triaxial ground reaction forces (GRF) and three-dimensional orientations of feet. To test accuracy of the new measurement system, verification experiments by using reference measurements of a commercially available measurement system were performed in a gait laboratory, where a stationary force plate and a motion capture system based on high-speed cameras are provided to analyse human movements. Experiment results supported that the developed system can be used to measure triaxial GRF with an acceptable precision during successive walking gait. An application trial was implemented to quantitatively analyze normal gaits and paralysis gaits using the M3D. Some quantitative differences between the gaits were analyzed based on results of three components of GRF and medial-lateral directional angular flexions of the feet.