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Tue, Apr 12

Speaker: Kevin McGill (Rehabilitation R&D Center, VA Palo Alto Health Care System)

Title:   EMG Decomposition: What can it tell us?  Can we trust it?

Abstract:   EMG decomposition is the process of sorting out the discharges of individual motor units from an EMG signal. It provides one of the few methods for studying the anatomy and behavior of individual motor units in humans.

This talk will discuss some of our experiences in using EMG decomposition to study the architectural organization of motor units in different human muscles, including brachioradialis (a series-fibered muscles) and biceps femoris (a pennate muscle), and the coordinated control of force production through common modulation of motor-unit firing rates ("common drive"), both within and between muscles.

This talk will also address the issue of EMG decomposition accuracy. Because EMG signals are so complex, decomposition accuracy is difficult to assess. Two objective approaches are to compare the results obtained from multiple EMG signals recorded simultaneously from the same muscle, and to rigorously assess the self consistency of the results obtained from a single signal. These approaches show that EMG decomposition can be trustworthy if the signal-to-noise ratio is high enough.

Host: William Z. Rymer & Ping Zhou