title: Does muscle morphology change in chronic neck pain patients? - A systematic review.
abstract: BACKGROUND
  Neck pain is a common disabling worldwide health problem with a high socio-economic burden. Changes underlying the transition to, or the maintenance of a chronic state are still barely understood. Increasing evidence suggests that morphological muscle changes, including changes in cross-sectional area (CSA) or fatty infiltration, play a role in chronic neck pain. However, a structured overview of the current evidence of morphological changes is lacking.
  
  
  OBJECTIVE
  To systematically review the morphological muscle changes in patients with chronic neck pain, including those with whiplash-associated disorders (WAD) and chronic idiopathic neck pain.
  
  
  METHODS
  A systematic review using the PRISMA-guidelines.
  
  
  RESULTS
  Fourteen of 395 papers were included after extensive screening. Most studies were of moderate methodological quality. A higher CSA was found in all flexor muscles in both patients with WAD and patients with chronic idiopathic neck pain, except for the deeper flexor muscles in patients with chronic idiopathic neck pain. The cervical extensor muscles show an increased CSA at the highest cervical segments in patients with WAD, while most studies in patients with chronic idiopathic neck pain report a decreased CSA in all extensor muscles. Fatty infiltration, which could be accountable for an increased CSA, of both cervical extensors and flexors seems to occur only in patients with WAD.
  
  
  CONCLUSIONS
  Some evidence is available for changes in muscle morphology, however more high quality prospective and cross-sectional research is needed to confirm these changes and to identify potential underlying causes that need yet to be discovered.
authors.affiliation: Ghent University, Department of Rehabilitation Sciences and Physiotherapy, De Pintelaan 185 3B3, 9000 Ghent, Belgium. Electronic address: Robby.DePauw@Ugent.be.
authors.forename: R
authors.initials: R
authors.lastname: De Pauw
authors.affiliation: Ghent University, Department of Rehabilitation Sciences and Physiotherapy, De Pintelaan 185 3B3, 9000 Ghent, Belgium. Electronic address: Iris.Coppieters@Ugent.be.
authors.forename: I
authors.initials: I
authors.lastname: Coppieters
authors.affiliation: Ghent University, Department of Rehabilitation Sciences and Physiotherapy, De Pintelaan 185 3B3, 9000 Ghent, Belgium. Electronic address: Jeroen.Kregel@Ugent.be.
authors.forename: J
authors.initials: J
authors.lastname: Kregel
authors.affiliation: Ghent University, Department of Rehabilitation Sciences and Physiotherapy, De Pintelaan 185 3B3, 9000 Ghent, Belgium. Electronic address: Kayleigh.DeMeulemeester@Ugent.be.
authors.forename: K
authors.initials: K
authors.lastname: De Meulemeester
authors.affiliation: Ghent University, Department of Rehabilitation Sciences and Physiotherapy, De Pintelaan 185 3B3, 9000 Ghent, Belgium. Electronic address: Lieven.Danneels@Ugent.be.
authors.forename: L
authors.initials: L
authors.lastname: Danneels
authors.affiliation: Ghent University, Department of Rehabilitation Sciences and Physiotherapy, De Pintelaan 185 3B3, 9000 Ghent, Belgium. Electronic address: Barbara.Cagnie@Ugent.be.
authors.forename: B
authors.initials: B
authors.lastname: Cagnie
mesh_terms: D000273:Adipose Tissue / Q000503:physiopathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries*; D059350:Chronic Pain / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009334:Neck Muscles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000293:injuries*; D019547:Neck Pain / Q000150:complications* / Q000503:physiopathology; D011446:Prospective Studies; D014911:Whiplash Injuries / Q000150:complications* / Q000503:physiopathology
keywords: Cross-sectional area; Fatty infiltration; Muscle morphology; Neck pain; Whiplash