Preliminary study of the effects of a placebo chiropractic treatment with sham adjustments

J Manipulative Physiol Ther. 1999 Sep;22(7):436-43. doi: 10.1016/s0161-4754(99)70031-x.


Objective: To identify aspects of the delivery of placebo chiropractic treatments by using sham adjustments that may cause a treatment effect and that may affect the success of blinding.

Design and setting: Two-period crossover design in a chiropractic college research clinic.

Subjects: Eighteen volunteer staff, students, and faculty of the chiropractic college who reported low-back pain within the last 6 months.

Interventions: Flexion-distraction technique was used to perform chiropractic adjustments, and a hand-held instrument (Activator adjusting instrument) with the pressure gauge set on the 0 was used to perform sham adjustments. The treatment period was 2 weeks, with a total of 4 visits.

Main outcome measures: The Visual Analog Scale (VAS) for pain and Global Well-Being Scale (GWBS).

Results: Although VAS and GWBS scores improved with both treatments, a somewhat greater improvement occurred in most cases with the active treatment. Eight of 14 patients interviewed believed that the placebo had a treatment effect.

Conclusion: This study provided preliminary information that was useful in planning the protocol for a placebo chiropractic treatment in the randomized clinical trial for which it was designed.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cross-Over Studies
  • Female
  • Humans
  • Low Back Pain / therapy*
  • Male
  • Manipulation, Spinal / methods*
  • Middle Aged
  • Pain Measurement
  • Patient Satisfaction
  • Placebos*
  • Reference Values
  • Treatment Outcome


  • Placebos