title: Measurement methods to assess diastasis of the rectus abdominis muscle (DRAM): A systematic review of their measurement properties and meta-analytic reliability generalisation.
abstract: METHODS
  Systematic literature review.
  
  
  BACKGROUND
  Diastasis of the rectus abdominis muscle (DRAM) has been linked with low back pain, abdominal and pelvic dysfunction. Measurement is used to either screen or to monitor DRAM width. Determining which methods are suitable for screening and monitoring DRAM is of clinical value.
  
  
  OBJECTIVE
  To identify the best methods to screen for DRAM presence and monitor DRAM width.
  
  
  METHODS
  AMED, Embase, Medline, PubMed and CINAHL databases were searched for measurement property studies of DRAM measurement methods. Population characteristics, measurement methods/procedures and measurement information were extracted from included studies. Quality of all studies was evaluated using 'quality rating criteria'. When possible, reliability generalisation was conducted to provide combined reliability estimations.
  
  
  RESULTS
  Thirteen studies evaluated measurement properties of the 'finger width'-method, tape measure, calipers, ultrasound, CT and MRI. Ultrasound was most evaluated. Methodological quality of these studies varied widely. Pearson's correlations of r = 0.66-0.79 were found between calipers and ultrasound measurements. Calipers and ultrasound had Intraclass Correlation Coefficients (ICC) of 0.78-0.97 for test-retest, inter- and intra-rater reliability. The 'finger width'-method had weighted Kappa's of 0.73-0.77 for test-retest reliability, but moderate agreement (63%; weighted Kappa = 0.53) between raters. Comparing calipers and ultrasound, low measurement error was found (above the umbilicus), and the methods had good agreement (83%; weighted Kappa = 0.66) for discriminative purposes.
  
  
  CONCLUSIONS
  The available information support ultrasound and calipers as adequate methods to assess DRAM. For other methods limited measurement information of low to moderate quality is available and further evaluation of their measurement properties is required.
authors.affiliation: Department of Rehabilitation, Nutrition and Sport, School of Allied Health, La Trobe University, Bundoora, Victoria, Australia.
authors.forename: A T M
authors.initials: AT
authors.lastname: van de Water
authors.affiliation: Department of Rehabilitation, Nutrition and Sport, School of Allied Health, La Trobe University, Bundoora, Victoria, Australia; Physiotherapy Department, Angliss Hospital, Eastern Health, Upper Ferntree Gully, Victoria, Australia. Electronic address: deenikabenjamin@optusnet.com.au.
authors.forename: D R
authors.initials: DR
authors.lastname: Benjamin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064131:Back Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000070630:Diastasis, Muscle / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017568:Rectus Abdominis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015203:Reproducibility of Results; D014463:Ultrasonography; D055815:Young Adult
keywords: DRAM; Psychometrics; Reliability; Validity; Women's health