The Patient Expectation in Dry Needling and Analgesia

This study will evaluate placebo mechanisms related to dry needling(DN) trying to determinate whether an additive effect occurs when DN is provided with an instructional set known to enhance placebo analgesia. External manipulation of patient expectation for receiving DN will be performed, in a similar way as has been already done in studies investigating the influence of expectation on spinal manipulative therapy interventions. The main purpose of this study will be therefore to determine, for the first time, how subjects' expectation about the effect of DN influences the resultant hypoalgesia. Analgesic effects of DN will be assessed using the conditioned pain modulation (CPM) paradigm, which has not been previously evaluated in relation to DN.