The relationship between muscle discrimination ability and response to relaxation training in three kinds of headaches.

Accurate discrimination of changes in physiological response has been noted as an important element in learning to control that response. Using a magnitude production procedure involving forearm isometric contractions, it was found that the ability to discriminate muscle tension varied across headache groups, with the no-headache control group (r = .76) being most accurate, followed by the tension group (r = .68), the mixed tension and migraine group (r = .60), and finally the migraine group (r = .51). The most important result, however, was that muscle discrimination ability significantly predicted clinical outcome from treatment by relaxation training for tension headache subjects (r = .50) but did not predict outcome for migraine or mixed headache subjects.