title: Establishing Immediate Reliability of Sonographic Measurements of the Transversus Abdominis in Asymptomatic Adults Performing Upright Loaded Functional Tasks in a Clinical Context Without Delayed Recorded Measurement.
abstract: OBJECTIVE
  This study examined the reliability of sonographic measurements of the transversus abdominis of adults without low back pain during upright loaded functional tasks in real time, without relying on delayed recorded images.
  
  
  METHODS
  A single-group repeated-measures reliability study was conducted on 12 healthy participants without low back pain. Six of these adults reported a prior history of abdominal drawing-in maneuver training without sonographic measurement. The participants performed 3 trials of neutral standing, a loaded forward reach, and a loaded box lift under rest and with abdominal drawing-in maneuver instructions; task order was randomized. Transversus abdominis thickness measurements were obtained by an experienced rater using B-mode sonography in real-time via electronic calipers twice on the same static image during all trials by a rater. The rater was masked to group assignment and on-screen measurement output and required to respond to trivia questions between repeated measurements.
  
  
  RESULTS
  The participants included 6 male and 6 female adults with a mean age ± SD of 26.3 ± 3.7 years. Intra-rater intraclass correlation coefficients (2,3) were high and precise for the rater's first and second measurements for all tasks and instruction conditions for mean transversus abdominis thickness and percent change in thickness measurements (eg, ranges were 0.968-0.997 for intraclass correlation coefficients, 0.01-0.21 mm for standard errors of the measurement, and 0.01-0.58 mm for minimal detectable changes). Calipers cleared by the rater or a research assistant produced similar findings of excellent reliability and precision.
  
  
  CONCLUSIONS
  High intra-rater reliability and precision of transversus abdominis thickness measurements were obtained by a physical therapist in real time from asymptomatic adults performing upright loaded functional tasks under rest and with abdominal drawing-in maneuver instructions.
authors.affiliation: Department of Physical Therapy, Western Carolina University, Cullowhee, North Carolina USA mcpherson@wcu.edu.
authors.forename: Sue
authors.initials: S
authors.lastname: McPherson
authors.affiliation: Department of Physical Therapy, Western Carolina University, Cullowhee, North Carolina USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Watson
authors.affiliation: Greenville Health System, Greenville, South Carolina USA.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Pate
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging* / Q000502:physiology*; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods*
keywords: abdominal drawing-in maneuver; functional tasks; musculoskeletal ultrasound; reliability; sonography; transversus abdominis