Response of pain to static magnetic fields in postpolio patients: a double-blind pilot study.

OBJECTIVE To determine if the chronic pain frequently presented by postpolio patients can be relieved by application of magnetic fields applied directly over an identified pain trigger point. DESIGN Double-blind randomized clinical trial. SETTING The postpolio clinic of a large rehabilitation hospital. PATIENTS Fifty patients with diagnosed postpolio syndrome who reported muscular or arthritic-like pain. INTERVENTION Application of active or placebo 300 to 500 Gauss magnetic devices to the affected area for 45 minutes. MAIN OUTCOME MEASURE Score on the McGill Pain Questionnaire. RESULTS Patients who received the active device experienced an average pain score decrease of 4.4 +/- 3.1 (p < .0001) on a 10-point scale. Those with the placebo devices experienced a decrease of 1.1 +/- 1.6 points (p < .005). The proportion of patients in the active-device group who reported a pain score decrease greater than the average placebo effect was 76%, compared with 19% in the placebo-device group (p < .0001). CONCLUSIONS The application of a device delivering static magnetic fields of 300 to 500 Gauss over a pain trigger point results in significant and prompt relief of pain in postpolio subjects.