The influence of expectation on spinal manipulation induced hypoalgesia: an experimental study in normal subjects.

Published online

Journal Article

BACKGROUND: The mechanisms thorough which spinal manipulative therapy (SMT) exerts clinical effects are not established. A prior study has suggested a dorsal horn modulated effect; however, the role of subject expectation was not considered. The purpose of the current study was to determine the effect of subject expectation on hypoalgesia associated with SMT. METHODS: Sixty healthy subjects agreed to participate and underwent quantitative sensory testing (QST) to their leg and low back. Next, participants were randomly assigned to receive a positive, negative, or neutral expectation instructional set regarding the effects of a specific SMT technique on pain perception. Following the instructional set, all subjects received SMT and underwent repeat QST. RESULTS: No interaction (p = 0.38) between group assignment and pain response was present in the lower extremity following SMT; however, a main effect (p < 0.01) for hypoalgesia was present. A significant interaction was present between change in pain perception and group assignment in the low back (p = 0.01) with participants receiving a negative expectation instructional set demonstrating significant hyperalgesia (p < 0.01). CONCLUSION: The current study replicates prior findings of c- fiber mediated hypoalgesia in the lower extremity following SMT and this occurred regardless of expectation. A significant increase in pain perception occurred following SMT in the low back of participants receiving negative expectation suggesting a potential influence of expectation on SMT induced hypoalgesia in the body area to which the expectation is directed.

Full Text

Duke Authors

Cited Authors

  • Bialosky, JE; Bishop, MD; Robinson, ME; Barabas, JA; George, SZ

Published Date

  • February 11, 2008

Published In

Volume / Issue

  • 9 /

Start / End Page

  • 19 -

PubMed ID

  • 18267029

Pubmed Central ID

  • 18267029

Electronic International Standard Serial Number (EISSN)

  • 1471-2474

Digital Object Identifier (DOI)

  • 10.1186/1471-2474-9-19

Language

  • eng

Conference Location

  • England