Back to Journals » Open Access Journal of Sports Medicine » Volume 1

Placebo effect of an inert gel on experimentally induced leg muscle pain

Authors Hopker J, Foad A, Beedie C, Coleman D, Leach G

Published 19 November 2010 Volume 2010:1 Pages 215—221

DOI https://doi.org/10.2147/OAJSM.S13564

Review by Single-blind

Peer reviewer comments 2


James G Hopker1, Abigail J Foad2, Christopher J Beedie2, Damian A Coleman2, Geoffrey Leach1
1Centre for Sports Studies, University of Kent, Chatham, Kent, UK; 2Department of Sports Science, Tourism and Leisure, Canterbury Christ Church University, Canterbury, Kent, UK

Purpose: This study examined the therapeutic effects of an inert placebo gel on experimentally induced muscle pain in a sports therapy setting. It aimed to investigate the degree to which conditioned analgesia, coupled with an expectation of intervention, was a factor in subsequent analgesia.
Methods: Participants were sixteen male and eight female sports therapy students at a UK University. With institutional ethics board approval and following informed consent procedures, each was exposed to pain stimulus in the lower leg in five conditions, ie, conditioning, prebaseline, experimental (two placebo gel applications), and postbaseline. In conditioning trials, participants identified a level of pain stimulus equivalent to a perceived pain rating of 6/10. An inert placebo gel was then applied to the site with the explicit instruction that it was an analgesic. Participants were re-exposed to the pain stimulus, the level of which, without their knowledge, had been decreased, creating the impression of an analgesic effect resulting from the gel. In experimental conditions, the placebo gel was applied and the level of pain stimulus required to elicit a pain rating of 6/10 recorded.
Results: Following application of the placebo gel, the level of pain stimulus required to elicit a pain rating of 6/10 increased by 8.2%. Application of the placebo gel significantly decreased participant’s perceptions of muscle pain (P = 0.001).
Conclusion: Subjects’ experience and expectation of pain reduction may be major factors in the therapeutic process. These factors should be considered in the sports therapeutic environment.

Keywords: conditioning, expectation, perception, positive belief, sports therapy

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]