J Manipulative Physiol Ther. 1995 Sep; 18(7): 453-6.

The immediate effect of activator vs. meric adjustment on acute low back pain: a randomized controlled trial.

Gemmell HA, Jacobson BH.

Department of Health, Physical Education and Recreation, Oklahoma State University, USA.

OBJECTIVE: To compare the immediate effects on pain of Meric and Activator adjustments in patients with acute low back pain (LBP). DESIGN: Adjustments were compared using a randomized, controlled clinical trial for relative effectiveness. SETTING: The study was conducted at a private chiropractic clinic in Tulsa, Oklahoma. PATIENTS: Thirty consecutive established patients presenting with acute LBP were studied. Sixteen subjects were randomly assigned to the Meric group and 14 to an Activator group. The mean (SD) age was 53.5 (9.5) for the Activator group and 51.8 (10.3) for the Meric group. INTERVENTION: The subjects received either a single Meric or Activator adjustment to the posterior joints involved. MAIN OUTCOME MEASURES: Before and immediately after the adjustments, subjects rated their pain intensity on a visual analog pain scale. RESULTS: The mean reduction in pain for the Activator group was means = 22.2, SD = 21.7; for the Meric group means = 21.8, SD = 21.5. The results indicate that there is no significant difference between Meric and Activator adjustments in reducing acute LBP (F = .005, df = 2, 27, p = .941). CONCLUSION: This study demonstrated no advantage of one procedure over the other for the reduction of pain.