Changes in EEG power density spectrum during static muscle work.

Changes in parameters of the EEG power density spectrum were demonstrated in four healthy male subjects during fatiguing static muscle contractions (M. biceps brachii dexter). For the following EEG frequency bands (delta 1-4 Hz, theta 4-8 Hz, alpha 8-13 Hz, beta 13-20 Hz), the relative power and the peak frequencies were determined. A significant increase in the alpha peak frequency was observed during muscle work. This trend was evident in both the central leads (C3-A1, C4-A1) and the occipital (O1-A1), particularly when the subjects had their eyes closed. These changes in peak frequency might be connected with an increase in central nervous activation.