In 1995, Gemmell, et. al., controlled trial conducted at a private chiropractic clinic in Tulsa, Oklahoma, researchers sought to compare the immediate effects of Meric and Activator adjustments on patients experiencing acute low back pain (LBP). The study aimed to determine the relative effectiveness of these two chiropractic techniques in alleviating pain in individuals with this common ailment.

Thirty consecutive established patients with acute LBP participated in the study, with 16 randomly assigned to the Meric group and 14 to the Activator group. The mean age of the Activator group was 53.5 years (SD = 9.5), while the Meric group had a mean age of 51.8 years (SD = 10.3). Each subject received a single Meric or Activator adjustment targeting the posterior joints associated with their pain.

To assess the immediate impact of the adjustments, subjects were asked to rate their pain intensity on a visual analog pain scale both before and after the chiropractic interventions.

The analysis of pain reduction revealed that the mean reduction in pain for the Activator group was means = 22.2 (SD = 21.7), while for the Meric group, it was means = 21.8 (SD = 21.5). Surprisingly, the results indicated no significant difference between Meric and Activator adjustments in reducing acute LBP (F = .005, df = 2, 27, p = .941).

Contrary to expectations, the study found no discernible advantage of one procedure over the other for the reduction of pain in acute LBP. This suggests that both Meric and Activator adjustments have comparable immediate effects in alleviating low back pain. These findings contribute valuable insights to the field of chiropractic care, emphasizing the need for further exploration and consideration of diverse treatment options for individuals experiencing acute LBP.

Reference: Gemmell, H. A., & Jacobson, B. H. (1995). The immediate effect of activator vs. meric adjustment on acute low back pain: a randomized controlled trial. Journal of manipulative and physiological therapeutics, 18(7), 453-456.