Single-Channel Techniques for Information Extraction from the Surface EMG Signal

This chapter describes some of the most commonly used techniques for processing single-channel surface electromyographic (sEMG) signals. The single-channel techniques address the interference pattern that results from the simultaneous activation of many motor units (MUs). The chapter reviews spectral estimation and traditional stochastic models applicable to the electromyographic (EMG) signal. These models are used to develop, interpret, and test most of the signal processing techniques. EMG amplitude estimates have been assessed via a common application: the use of surface EMG to estimate joint torques. The chapter explores the basic body of knowledge concerning EMG spectral analysis and how physiological parameters are reflected by surface EMG power spectra. It further focuses on the theoretical basis for the assessment of muscle fatigue during high-intensity isometric constant force contractions since this assessment is by far the most prevalent application of surface EMG spectral analysis.