title: Reliability of the ultrasound measurements of abdominal muscles activity when activated with and without pelvic floor muscles contraction.
abstract: BACKGROUND
  Synergistic co-activation of the abdominal and pelvic floor muscles (PFM) has been shown in literature. Some studies have assessed the reliability of ultrasound measures of the abdominal muscles.
  
  
  OBJECTIVE
  The aim of this study was to determine the reliability of ultrasound measurements of transverses abdominis (TrA) and obliquus internus (OI) muscles during different conditions (PFM contraction, abdominal hollowing manoeuvre (AHM) with and without PFM contraction) in participants with and without chronic low back pain (LBP).
  
  
  METHODS
  21 participants (9 with LBP, 12 healthy) participated in the study. The reliability of thickness measurements at rest and during each condition and thickness changes and percentage of this changes at different conditions were assessed.
  
  
  RESULTS
  The results showed high reliability of the thickness measurement at rest and during each condition of TrA and OI muscles, moderate to substantial reliability for the thickness change and percentage of thickness change of TrA, and fair to moderate reliability of the thickness change and percentage of thickness change of OI in both groups.
  
  
  CONCLUSIONS
  Ultrasound imaging can be used as a reliable method for assessment of abdominal muscle activity with and without PFM contraction.
authors.affiliation: Department of Physical Therapy, Faculty of Rehabilitation Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Tahan
authors.affiliation: Department of Physical Therapy, Faculty of Health Education and Social Work, Sør-Trøndelag University College (HiST), Trondheim, Norway.
authors.forename: Omid
authors.initials: O
authors.lastname: Rasouli
authors.affiliation: Department of Physical Therapy, University of Social Welfare and Rehabilitation Sciences, Evin, Tehran, Iran.
authors.forename: Amir Massoud
authors.initials: AM
authors.lastname: Arab
authors.affiliation: Department of Physical Therapy, Faculty of Rehabilitation Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Khosro
authors.initials: K
authors.lastname: Khademi
authors.affiliation: Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Elham Neisani
authors.initials: EN
authors.lastname: Samani
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000293:Adolescent; D000328:Adult; D059350:Chronic Pain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D017773:Pelvic Floor / Q000503:physiopathology*; D015203:Reproducibility of Results; D014463:Ultrasonography; D055815:Young Adult
keywords: Low back pain; abdominal muscles; pelvic floor muscles; reliability