Surface EMG pre-processing techniques for the detection of common input to motor neuron populations

In this paper we compared four surface EMG preprocessing techniques to improve the detection of common input to two motor neuron populations. We proposed multichannel approach named Activity index and its improvement higherorder Activity index. Both methods were compared to raw and rectified EMG. Techniques were evaluated on simulated EMG signals of two motor neuron populations and EMG-EMG coherence was used as a measure. Higher-order Activity index performed better than original Activity index, coherence values were in the range of rectified EMG.