A mother wavelet selection study for vertical ground reaction force signals

Abstract

Wavelet transform (WT) is a recent mathematical tool widely used in biomedical field. Its application enormously spans the field of signal and image processing. The first step in applying this transform is to select the appropriate mother wavelet (MW). However, there is no standard method in the literature that could be used to choose a convenient MW for the analysis of a given data. While few techniques have been proposed, the present work aims to select the optimum MW for Vertical Ground Reaction Force (VGRF) signals through the computation of the maximum compression ratio (CR). In this study, fifty-three orthogonal MWs have been analyzed using the discrete wavelet transform (DWT). Then, sequential steps have been applied on hundred signals extracted from participants walking at their usual speed. The obtained results show that sym1, db1, bior1.1 and rbio1.1 compress maximally the VGRF signals (50.56%). Therefore, the use of these MWs for VGRF signal analysis is recommended.