Pain and the placebo in rehabilitation using TENS and laser

The placebo effect of many health-related treatments is generally acknowledged. This paper discusses the role of the placebo in relation to pain perception and pain control. The theoretical basis of the placebo response is examined, followed by a discussion of the factors influencing the placebo response. Finally, the magnitude of the placebo response is explored specifically in relation to outcome measures and the efficacy of transcutaneous electrical nerve stimulation (TENS) and laser for pain relief.