Spinal Manual Therapy Under Sedation

Several health care professions use manual therapy techniques (joint manipulation and mobilization, and soft tissue treatment) to successfully treat back and neck pain. However, it is still unknown how manual techniques work. As with any type of treatment, there are at least two possible explanations. First, the treatment might cause physical changes in the body; for manual therapy, these would be changes in the joints, muscles, or other tissues. Second, patients might feel better because they believe the treatment will help. In drug trials, it is relatively easy to determine the extent to which patients' beliefs contribute to treatment effects: patients can be given a dummy pill with no active ingredient (a "placebo"). In this way, patients are "blinded," meaning that they do not know whether they received the real drug or not. In manual therapy studies, however, blinding is difficult because patients can feel whether or not they are receiving real treatment. This problem can be overcome by sedating patients: while asleep, patients receive either real hands-on manual therapy or no treatment. Because patients do not know which treatment they received, it becomes possible to determine whether any benefits result from changes in the body or from patients' expectations.

In this pilot study, 20 participants with low back or neck pain lasting at least three months will be sedated for approximately 15 minutes. Half of them (the "true group") will receive manual therapy to the spine. The other half (the "sham group") will be sedated for the same length of time but will not receive any treatment. Before and after the intervention, and again at a follow-up visit two weeks later, spinal mobility will be assessed and blood samples will be collected to measure substances known to change after spinal manipulative therapy. At these time points, and again at three and six months, participants will complete questionnaires about their pain, how much the pain limits them, any side effects they notice, which treatment they believe they received, and how they experienced the intervention and the period that followed.

The purpose of this pilot study is twofold. First, the study will assess whether enough participants can be recruited and retained for the full study duration, and whether they remain unaware of their group allocation. If participants correctly guess which group they were in, this would indicate that they were not truly blinded. Second, preliminary data from the questionnaires, mobility tests, and blood samples will be collected to explore potential differences between the true and sham groups. These results will help in designing a larger follow-up study, which is planned if this pilot study is successful. Such a study could then determine whether manual therapy works through physiological changes in the body, through patient expectations, or through a combination of both. Participants in this pilot study may benefit directly through reduced pain and/or improved spinal mobility. More broadly, the knowledge gained from this pilot study may ultimately lead to improved treatments and better clinical outcomes for patients with spinal pain.