Review article (meta-analysis)
Prevalence of Myofascial Trigger Points in Spinal Disorders: A Systematic Review and Meta-Analysis

Presented as an abstract and poster to the World Confederation of Physical Therapy Congress, May 1–4, 2015, Singapore.
https://doi.org/10.1016/j.apmr.2015.09.021Get rights and content

Abstract

Objective

To retrieve, appraise, and synthesize the results of studies on the prevalence of active and latent myofascial trigger points (MTrPs) in subjects with spinal pain disorders.

Data Sources

The databases PubMed, Embase, and CINAHL were searched, with no date or language restrictions. Search terms included controlled and free-text terms for spinal disorders and MTrPs. Further searches were conducted in Google Scholar and by contacting 3 experts in the field. Citation tracking of eligible studies was performed.

Study Selection

Two reviewers independently selected observational studies assessing the prevalence of active and/or latent MTrPs in at least 1 group of adults with a spinal disorder. Twelve studies met the eligibility criteria.

Data Extraction

Methodologic quality was assessed by 2 reviewers independently using a modified version of the Downs and Black checklist. Two reviewers also used a customized form to extract studies and subjects' characteristics and the proportions of subjects with active and/or latent MTrPs in each muscle assessed.

Data Synthesis

A meta-analysis was performed when there was sufficient clinical homogeneity in at least 2 studies for the same spinal disorder. The Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the body of evidence in each meta-analysis. A qualitative description of the results of single studies was provided. Low-quality evidence underpinned pooled estimates of MTrPs in the upper-body muscles of subjects with chronic neck pain. The point prevalence of MTrPs in different muscles of other disorders (eg, whiplash-associated disorders, nonspecific low back pain) was extracted from single studies with low methodologic quality and small samples. Active MTrPs were found to be present in all assessed muscles of subjects diagnosed with different spinal pain disorders. Latent MTrPs were not consistently more prevalent in subjects with a spinal disorder than in healthy controls.

Conclusions

The MTrPs point prevalence estimates in this review should be viewed with caution because future studies with large samples and high methodologic quality are likely to change them substantially.

Section snippets

Methods

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines.23 A protocol was written a priori and is available in Appendix 1 Presence of MTrPs in Different Spinal Health Conditions: Protocol for a Systematic Review, Methods Protocol, Appendix 2 Queries for the Bibliographic Databases, Appendix 3 Checklist for Assessing Study Quality, Modified From Downs and Black.

Results

Figure 1 is a flowchart of study retrieval, screening, and eligibility. The 3 experts in the field we contacted did not identify any additional studies besides those retrieved from the database searches and citation tracking. Twelve studies met the eligibility criteria and were included in this review40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51; 4 of these studies40, 42, 44, 49 were included in the meta-analyses. All studies were cross-sectional and assessed the point prevalence of MTrPs. The

Discussion

In this systematic review we aimed to synthesize the evidence on the prevalence of active and latent MTrPs in spinal disorders by including 12 cross-sectional studies assessing point prevalence in 6 different spinal pain disorders. Low-quality evidence was found for the pooled point prevalence of active MTrPs of different muscles in subjects with chronic NP. Point prevalences of active MTrPs in subjects with WAD and NSLBP were extracted from single studies that had low quality and/or very small

Conclusions

This systematic review shows that active and latent MTrPs can be present in different spinal disorders (eg, NP, WAD, NSLBP). However, these findings are at best underpinned by pooled estimates of point prevalence that are based on low-quality evidence, according to the Grading of Recommendations Assessment, Development and Evaluation approach. Most of the estimates for both active and latent MTrPs are based on individual studies with very small sample sizes and low methodologic quality. Future

Suppliers

  • a.

    EndNote; Thomson Reuters.

  • b.

    Comprehensive Meta-Analysis 2.0; Biostat.

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    Supported by the Thim van der Laan Foundation.

    This funding body did not have any role in design, conduction, analysis, and interpretation of data nor in writing this manuscript and deciding to submit this manuscript for publication. The views expressed here are those of the authors and do not necessarily reflect those of their funding bodies.

    Disclosures: none.

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