Knee pathology diagnosis based on muscle activation intervals detection and the relationship between knee flexion and surface EMG

Abstract

Muscle activation interval (MAI) is an important clinical indicator for muscular disorders diagnosis. In this study, the S-transform technique was proposed to detect the muscle activation onset and offset timing during gait and determine the relationship between surface electromyographic (sEMG) signals and knee pathology. The results obtained show that the proposed method achieved the shortest average latency (τonset = 0.015 s, τoffset = 0.014 s) compared to the recent methods: SampEn, Teager-Kaiser energy operator (TKEO), and integrated profile. Moreover, the statistical analysis of activation intervals diversity and correlation between sEMG and knee flexion signals provide that for abnormal cases, the linear relationship is very weak and the activation intervals become more diverse.