Article ID: JJPTF_2024_S4
Recently, a non-invasive algorithm has been developed for the analysis of motor unit firing behavior, which employs a high-density surface electromyography (HD-sEMG). A validated convolutive blind source separation method can separately the HD-sEMG recordings into individual motor unit discharge timings. In general, intramuscular EMG has been used for detailed evaluation of motor unit firing behavior, but it has several disadvantages, such as painful method, sampling bias, and limitation of motor tasks. HD-sEMG with more than 60 surface electrodes allow this technique to increase the number of detectable motor units compared to intramuscular EMG and to investigate detailed motor unit firing characteristics, such as the relationship of firing rates between motor units with different recruitment thresholds. Therefore, HD-sEMG method can be used to noninvasively identify the activity of the motor units and can be used to uncover unknown mechanisms of the central nervous system in physiology field. It is the purpose of this review to provide an overview of the characteristics of the firing behavior of the motor unit, both in healthy individuals and in patients with neurodegenerative diseases in this review.
