Does muscle tension reflect arousal? Relationship between electromyographic and electroencephalographic recordings

Increased muscle tension and heightened arousal are the most consistent finding in patients with anxiety disorders. This study examined the relationship between frontalis and gastrocnemius electromyographic (EMG) and electroencephalographic activity on 14 female generalized anxiety disorder patients and 14 female control subjects. In GAD patients, gastrocnemius but not frontalis EMG was correlated with right but not left hemisphere activity. For the non-anxious subjects, there was a pattern for both beta 1 and beta 2 waves to be positively associated with both frontalis and gastrocnemius muscle tension levels. The results, while preliminary, suggest that EMG activity may reflect central nervous system arousal.