Validation Study for Novel Designed Tri-Axis Force Plate and Development of Algorithm for Decomposing Ground Reaction Force on a Single Force Plate

Abstract

This developed an algorithm to solve the footstep targeting problem by gait analysis of the novel force plate. Using the force plate and the novel force plate to measure 11 healthy participants, and each subject was required to perform three times of counter movement jumps (CMJ), and walks without footstep targeting on two force platforms. First of all, the data of Ground Reaction Force (GRF) from Counter Movement Jump (CMJ) performance would be collected, and be calculated the parameter, including body weight, flight time, and the peak value of the vertical component to validate the novel tri-axis force plate. Second, in the algorithm development, vertical GRF measure and vertical GRF computed during normal gait analysis from the motion force plate were compared with each other, and the algorithm was used to calculate the decompose force when stepping on the novel force plate. Finally, the decomposed force with the corresponding measure with motion would be verified. It was analyzed by Spearman rank correlation coefficient, and the results were: body weight (R = 0.99, p < 0.01), flight time(R = 0.92, p < 0.01), and peak value of the vertical ground reaction force (R = 0.91, p < 0.01). Additionally, the mean relative error between the vertical GRF and the corresponding was 6.77 ± 7.49%. Therefore, the decomposed vertical GRF of both force plate and novel force plate were compared and that disclosed the algorithm of decomposed the vertical GRF. At compared the cross correlation coefficients with decomposed GRF on novel force plate by algorithm and measured on motion lab, the result showed that the right footstep variations of cross correlation coefficients was 0.98 and left footstep was 0.99, so In this study, the novel force plate indeed has high validity representation by the experiments examine, and the algorithm to decompose the vertical ground reaction forces was validated when subjects stepping on the single novel force plate. It try to solve the “Targetting Step”.