Brantley ME, Cheben DL, Gay HF, Wright LL, Thompson AW, Lake DA; Department of Physical Therapy, Armstrong Atlantic State University, Savannah, GA. lakedavi@mail.armstrong.edu.

PURPOSE: This study was a randomized, double-blind, clinical trial to test the effects of therapeutic static magnets on myofascial trigger points (MTPs). SUBJECTS/METHODS: Thirty subjects with MTPs were randomly assigned to therapeutic static magnet (14) or sham magnet control (16) groups. Both the experimenters and subjects were unaware of the nature of the magnet or group assignment. A single identified MTP on each subject was tested with a pressure algometer, and the subjects were asked to indicate when pressure became pain (pain threshold). Subjects filled out the McGill pain questionnaire, the Present Pain Index (PPI) from the McGill pain questionnaire and a visual analog scale (VAS) indicating their pain level at that point before and after exposure to either a 300 Gauss static magnet or a sham magnet for 45 minutes. ANALYSES: Pre-test/Post-test differences in pain levels for each measurement were compared using the Wilcoxon rank sign for both control and magnet groups. Pre-test measures between the magnet and control groups were compared using the Mann-Whitney U. RESULTS: There were no significant differences in the pain level upon algometer pressure application between the pre-test measures for all measures between the magnet and sham magnet groups. There was a significant decrease in the McGill overall score (p = .0168) and the PPI (p = .0461) following a 45 minute exposure to the 300 Gauss therapeutic magnet, but there was no change in the VAS (p = .1621) and there was no change in any measures in subjects treated with the sham magnets. Moderate pre/post-test effect sizes were seen in the McGill total score (d=.53) and the PPI (d=.61) and a small effect size was seen in the VAS (d = .31) in the magnet group. CONCLUSIONS: This study suggests that 300 gauss therapeutic static magnets can decrease the pain associated with pressure applied to myofascial trigger points. This is consistent with a previous study by Valbona, et al. (1997) who reported a decrease in pain in myofascial trigger points in a post-polio population. This study expands upon those results to suggest that static therapeutic magnets may have a beneficial effect in reducing pain in a wider range of patients with myofascial trigger points. FUNDING SOURCE: Magnets were provided by Bioflex Corporation, Ft Lauderdale, FL.

Copyright 2004 by the American Physical Therapy Association

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