An experimental investigation of pain production in headache patients.

An experiment was conducted to test two assumptions underpinning the prevailing medical model of tension headache: (1) that tension headache pain is due to sustained contraction of the skeletal muscles of the scalp; (2) that the muscle contraction produces greater pain for tension headache patients than for migraineurs. Six tension headache patients and six migraine patients were compared with six matched non-headache control subjects. All subjects used visual EMG biofeedback to hold different levels of frontalis muscle contraction for periods of one and three minutes. Ratings of pain and subjective tension were obtained for all trials. The results provided little support for either hypothesis. Pain ratings were not clearly related to induced EMG levels, but there was clear evidence that subjective tension was a function of EMG activity. It is suggested that the role of psychological factors in the production of pain should be further explored.