A Comprehensive Assessment of Lower Limb Muscle Fatigue Through Fusion of sEMG and VMG Signals

The measurement of lower limb muscle fatigue is crucial for Human-Machine Interaction (HMI) and the prevention of muscle injuries. This study aims to explore a method for assessing lower limb fatigue based on surface electromyography (sEMG) and vibromyography (VMG) signals, with the aim of improving the accuracy and sensitivity of muscle fatigue assessment. The muscle fatigue induction experiment was conducted by subjecting participants to sustained isometric contractions at 50 % of their maximal voluntary contraction (MV C) to induce a state of complete muscle fatigue, with five subjects participating. We employed the wavelet scattering technique to extract features from the sEMG and VMG signals, subsequently analyzing the combination of peak amplitude, root mean square (RMS), and median frequency (MDF) as indicators of muscle fatigue. By analyzing the differences and correlations between these fatigue indicators, it is possible to correlate muscle contraction intensity and muscle synergy, thereby making a detailed and reliable physiological assessment of muscle fatigue and comprehensively understanding the fa-tigue mechanism. This study provides a new assessment method for sports medicine and rehabilitation engineering, and provides theoretical support for fatigue monitoring and rehabilitation training.