Comparison of algorithms for estimation of EMG variables during voluntary isometric contractions

Many algorithms have been described in the literature for estimating amplit ude, frequency variables and conduction velocity of the surface EMG signal detected during voluntary contractions. They have been used in different ap plication areas for the non invasive assessment of muscle functions. Althou gh many studies have focused on the comparison of different methods for inf ormation extraction from surface EMG signals, they have been carried out un der different conditions and a complete comparison is not available. It is the purpose of this paper to briefly review the most frequently used algori thms for EMG variable estimation, compare them using computer generated as well as real signals and outline the advantages and drawbacks of each. In p articular the paper focuses on the issue of EMG amplitude estimation with a nd without pre-whitening of the signal, mean and median frequency estimatio n with periodogram and autoregressive based algorithms both in stationary a nd non-stationary conditions, delay estimation for the calculation of muscl e fiber conduction velocity. (C) 2000 Elsevier Science Ltd. All rights rese rved.