The purpose of this work was to investigate myoelec tric signal (MES) activity and perceived discomfort in areas of common CTD complaints: the neck, the low back, the shoulder region, and the wrist. In particular, the first objective was to determine the effect of "microbreak" protocols on muscle activation behavior. The second objective was to determine the effect of "microbreaks" on perceived discomfort. The third objective was to determine the effect of "microbreaks" on worker produc tivity. It was hypothesized that microbreaks would be associated with an increase in the frequency of MNF cycling in the MES, would reduce the level of perceived discomfort, and would not negatively impact worker productivity.