Abstract
The ambulatory measurement of ground reaction force (GRF) and human motion under free-living condition is really desired for gait analysis. A wearable force plate system was developed by integrating small triaxial force sensors and 3D orientation sensors for estimating triaxial GRF and orientations of the foot. As for the measurement accuracy, we compared the developed system's measurements of the triaxial GRF and the center of pressure (CoP) with reference measurements by a stationary force plate and an optical motion analysis system. The RMS difference of the two transverse components (x- and y- axes) and the vertical component (z-axis) of the GRF was 4.3±0.9N, 6.0±1.3N, and 12.1±1.1N respectively, corresponding to 5.1±1.1% and 6.5±1% of the maximum of each transverse component, and to 1.3±0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP trajectories was 3.2±0.8mm, corresponding to 1.2±0.3% of the length of the shoe.
