Pain and the Placebo in Physiotherapy

Summary The aim of this paper is to discuss the mechanisms and magnitude of the placebo effect of treatment and to consider the ethical and moral implications of using placebo physiotherapy. Placebo or non-specific treatment effects were long considered to contribute a fixed fraction (one-third) to any treatment effect. Recent evidence has revealed this commonly held clinical belief to be erroneous. The placebo effect of any treatment is a highly variable and complex phenomenon that is influenced by a myriad factors. The outcome may be positive (eg analgesia) or negative (eg increased dependency on healthcare practitioners). Although the mechanisms of effect are not fully understood, evidence supports the influence of classical conditioning, anxiety reduction, and the expectations of both patients and practitioners. The relationship between patients and practitioners influences the magnitude of placebo effects as does the method of treatment presentation. A charismatic or caring practitioner can evoke analgesia with or without further treatment. And treatment presented with an air of ‘mystery‘, apparent sophistication, or positive expectation can evoke analgesia simply through the method of its presentation. Questions regarding the ethical use of treatments that are primarily placebo need to be addressed. When and under what conditions are placebo treatments acceptable in the short or long term? Is it a benevolent lie, or a regular lie, to use treatments that have only placebo effects? And, perhaps more importantly, do we know what those treatments are?