18 patients suffering from primary fibromyalgia received nine
training sessions using EMG biofeedback over a period of four
weeks. Pre- and posttreatment measurement of the baseline EMG
activity of the trapezius, muscular sensitivity, and cognitive
variables (helplessness and belief of control) were taken.
Analysis indicated a significant reduction occurred in general
intensity of pain and in EMG activity as well as a significant
increase in muscular sensitivity. Multiple regression analyses
indicated that the increase in muscular sensitivity correlated
with the decrease of EMG activity in the trapezius baseline.
Self-reported pain reduction was predicted by a change in