THE SHORT-TERM EFFECT OF A SPINAL MANIPULATION ON PAIN PRESSURE THRESHOLD IN PATIENTS WITH CHRONIC MECHANICAL LOW-BACK-PAIN

Objective: The purpose of this study was to evaluate the pain/pressure threshold of selected myofascial points in subjects with chronic mech anical back pain after a single manipulation or mobilization. Design: The study design was a randomized control trial. Setting: Chiropractic College outpatient clinic. Participants: Thirty subjects aged 18-50 y r (mean age 31 yr, SD = 7 yr) with chronic mechanical low back pain (m ean duration of pain 74 months, SD = 83 months) were randomized into t wo groups. One group received a manipulation and the other received a mobilization. Outcome measure: Pain/pressure threshold of selected myo fascial points were measured before, immediately after, and 15 and 30 min postintervention. Results: Sixteen patients were allocated to the manipulation group and 14 to the mobilization group. Repeated measured analysis of variance for all locations failed to show clinical or sta tistical significance (p > .287). The overall effect between treatment s and the interaction between treatment and time was not significant ( p > .268). Conclusion: The absence of significant changes may be attri buted to the selection of myofascial points, the instrument sensitivit y to small changes, the differences in baseline measures and the absen ce of effect from one intervention.