Is manual therapy largely a placebo? Are the sham interventions used to assess the effectiveness of manual therapy reliable comparisons? This study (PMID: 36360901) aimed to answer these questions. Specifically, the objective was to “evaluate whether the design of placebo control groups could produce different interpretations of the efficacy of manual therapy techniques.”
The review included randomized control trials assessing any patient population experiencing pain (experimental pain was excluded). The trials had to assess the effectiveness of a specific technique, such as joint mobilization or manipulation. Trials involving multiple therapies (e.g., manual plus exercise) were excluded. The trial must include at least one sham group involving an intervention. No treatment controls were excluded. Lastly, pain intensity had to be assessed using a validated, rating scale. All placebo interventions had to be able to be replicated, receive the same expectations as the treatment group, and not pose a greater risk for harm than the intervention.
The article search yielded 48 articles, comprising 1827 subjects. Wil neck and low back pain were the most common body regions treated, the studies covered many regions of the body including TMJ, shoulder, and knee. Most studies (63%) used a single intervention but the longest included 48 sessions over 10 months.
There were two primary methods for providing a sham manual therapy treatment. The most common (62.5%) was simulating the procedure without the rapid application of motion characteristic of the manipulation technique. The second approach (37%) was to reproduce the rapid application of motion during the simulation but without inducing the thrust.
The trials favored manipulation, but the effect sizes were small (0.42) and the heterogeneity was moderate (I2 = 65.2%). 21% of the trials were “not adequately” blinded and the difference in outcomes did not reach clinical significance. Also, the sham procedures that simulated the high-speed movement did not show statistical differences tween active and sham. Patients may perceive the skill needed or the type of technique differently. There is also the consideration of physical touch alone being a therapeutic benefit.
This study shows there is no clear-cut benefit to providing specific manual therapy techniques. In some cases, sham may be inferior but in others, it equals the outcomes of specific techniques.
Hands-on PT can enhance therapeutic alliance and reduce pain; however, we may not need to spend a lot of time and effort learning and perfecting specific techniques.