Spinal manipulative therapy versus a low force mimic maneuver for women with primary dysmenorrhea: a randomized, observer-blinded, clinical trial

Non-drug therapies for women with primary dysmenorrhea are primarily based on anecdotal evidence and small-scale clinical studies. This randomized, ob server-blinded, clinical trial evaluated the efficacy of spinal manipulativ e therapy (SMT) in the treatment of women with primary dysmenorrhea. Women were recruited from the Chicago metropolitan area and evaluated for inclusi on through four screening levels. One hundred thirty eight women, ages 18.- 45, with primary dysmenorrhea diagnosed by participating gynecologists, wer e randomly assigned to either SMT or a law-force mimic (LFM) maneuver. No t reatment occurred at menstrual cycle 1. Treatment for both groups took plac e on day 1 of cycles 2, 3 and 4, and prophylactic treatment of three visits took place during the 7 days before cycles 3 and 4. Main outcome measures were the Visual Analog Scale (VAS) and plasma concentration of the prostagl andin F-2 alpha metabolite, 15-keto-13,14-dihydro-prostaglandin F-2 alpha ( KDPGF(2 alpha)), measured 15 min before treatment and 60 min after treatmen t on day 1 of four consecutive menstrual cycles. The Moos' Menstrual Distre ss Questionnaire (MDQ) was also administered after treatment on day 1 of ea ch cycle. At cycle 2, the post-treatment VAS scores decreased for both grou ps, with no statistically significant difference in pre- to post-treatment scores between the two groups (P = 0.44). The changes in pre- to post-treat ment KDPGF(2 alpha), levels were not statistically different between the SM T and LFM groups (P = 0.15). No treatment effects were detected over the th ree cycles for VAS, KDPGF(2 alpha) or MDQ (P = 0.65, P = 0.61 and P = 0.78, respectively). However, there were statistically significant linear time e ffects for VAS (P = 0.008), MDQ (P < 0.001), and borderline significance fo r KDPGF(2 alpha) (P = 0.054); these decreases were not considered clinicall y meaningful. The LFM maneuver used in this study was designed to act as a 'placebo-like' control treatment in comparison with SMT. Although it is pos sible that the trial did not continue long enough for any placebo effect of the LFM to wash out, it seems more likely that this maneuver was indisting uishable from SMT. Therefore, the postulated superior benefit of high-veloc ity, short-lever, low-amplitude, high-force spinal manipulation to a low-fo rce maneuver is not supported by the results of this study. (C) 1999 Intern ational Association for the Study of Pain. Published by Elsevier Science B. V.