The Effect of the Estimated Innervation Zone on EMG Amplitude and Center Frequency.

The article discusses the effect of the estimated innervation zone (IZ) on electromyographic (EMG) amplitude and mean power frequency (MPF). Participants performed isometric muscle actions of the leg extensors wherein the surface EMG signals were recorded from the vastus lateralis muscle placed over the estimated IZ. Results of the test show the inconsistency on the differences on the patterns of response and mean values for EMG amplitude and MPF versus isometric torque over the estimated IZ from those away from the IZ. Moreover, these differences suggest that normalized EMG amplitude values are not comparable if the EMG signals are detected from different electrode locations.