Secondary Logo

Institutional members access full text with Ovid®

Share this article on:

Mechanism of Action of Spinal Mobilizations: A Systematic Review

Lascurain-Aguirrebeña, Ion, MSc*,†; Newham, Di, PhD; Critchley, Duncan John, PhD

doi: 10.1097/BRS.0000000000001151

Study design. Systematic review.

Objective. To review the evidence regarding the mechanism of action of mobilizations.

Summary of background data. Spinal mobilizations—low velocity passive oscillatory movements—reduce spinal pain in some patient subgroups. Identifying patients likely to respond remains a challenge since mobilizations’ mechanism(s) of action are unclear.

Methods. Medline, Web of Science, Cinahl, Embase, and Scopus databases were searched for relevant studies. Reference lists of included studies were hand searched. Studies were included if the intervention was passive spinal mobilizations, participants were symptomatic, and outcomes evaluated possible mechanisms of action. Methodological quality was independently assessed by two assessors using a modified Cochrane Back Review Group tool.

Results. Twenty-four studies were included in the review. Four were classified high risk, 14 moderate risk, and four low risk of bias. Commonest methodological limitations were lack of participant blinding, adequate randomization and allocation concealment, and sample size calculation. Evidence suggests that spinal mobilizations cause neurophysiological effects resulting in hypoalgesia (local and/or distal to mobilization site), sympathoexcitation, and improved muscle function. Mobilizations have no effect on temperature pain threshold. Three of four studies reported reduction in spinal stiffness, heterogeneous in location and timing. There is limited evidence (one study in each case) to suggest that mobilizations produce increased nociceptive flexion reflex threshold, improved posture, decreased concentration of substance P in saliva, and improved sway index measured in cervical extension. Evidence does not support an effect on segmental vertebral movement. Two studies investigated correlations between hypoalgesia and mechanism: one found a correlation with sympathoexcitatory changes, whereas the other found no correlation with change in stiffness.

Conclusion. These findings suggest involvement of an endogenous pain inhibition system mediated by the central nervous system, although this is yet to be investigated directly. There is limited evidence regarding other possible mechanisms.

Level of Evidence: 3

*Faculty of Medicine & Odontology, Department of Physiology, University of the Basque Country, Leioa, Spain

Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom.

Address correspondence and reprint requests to Ion Lascurain-Aguirrebena, MSc, Faculty of Medicine and Odontology, Department of Physiology, University of the Basque Country, Barrio Sarriena, s/n, Leioa 48940, Spain; E-mail:

Received 24 June, 2015

Revised 7 August, 2015

Accepted 7 August, 2015

The manuscript submitted does not contain information about medical device(s)/drug(s).

No funds were received in support of this work.

Relevant financial activities outside the submitted work: grants.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (

Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.