Relationship between self-reported intensity of headache and magnitude of surface EMG

The study was designed to examine the relationship between self-reported intensity of headache and surface EMG. 98 patients, diagnosed by their neurologists with "muscle-contraction headaches" (tension-type headaches) were referred to evaluate their suitability for biofeedback therapy. At the time of examination, they were asked to rate their average headache intensity on a 10-point scale. Surface EMG data were collected to assess actual muscle contraction. Analysis indicated that among patients diagnosed with muscle contraction headache, there is a positive significant correlation between self-reported intensity of headache and actual muscle-contraction. The current data lend support to the hypothesis that the tension in the headaches currently described as "tension-type" may in fact refer to actual muscular tension or contraction.