title: Prevalence of Myofascial Trigger Points in Spinal Disorders: A Systematic Review and Meta-Analysis.
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.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
authors.affiliation: Department of Health Sciences, Faculty of Earth and Life Sciences, EMGO(+) Institute for Health and Care Research, Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Chiarotto
authors.affiliation: Department of Business, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland.
authors.forename: Ron
authors.initials: R
authors.lastname: Clijsen
authors.affiliation: Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain; Cátedra de Investigación y Docencia en Fisioterapia: Terapia Manual y Punción Seca, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
authors.forename: Cesar
authors.initials: C
authors.lastname: Fernandez-de-Las-Penas
authors.affiliation: Rehabilitation Research Laboratory, Department of Business, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Manno, Switzerland. Electronic address: marco.barbero@supsi.ch.
authors.forename: Marco
authors.initials: M
authors.lastname: Barbero
mesh_terms: D006801:Humans; D009209:Myofascial Pain Syndromes / Q000175:diagnosis* / Q000503:physiopathology; D010808:Physical Examination / Q000379:methods; D015995:Prevalence; D013122:Spinal Diseases / Q000503:physiopathology*; D061028:Trigger Points / Q000503:physiopathology*
keywords: Low back pain; Neck pain; Prevalence; Rehabilitation; Trigger points; Whiplash injuries