title: Comparison of the thickness of lateral abdominal muscles between pregnant women with and without low back pain.
abstract: OBJECTIVE
  To compare the thickness of the external oblique, internal oblique, and transversus abdominis muscles in pregnant subjects with and without low back pain (LBP) by the use of ultrasound to measure thickness.
  
  
  METHODS
  A case-control study.
  
  
  METHODS
  An academic and tertiary care referral spine and sports medicine center.
  
  
  METHODS
  Fifty pregnant women with LBP during pregnancy and 54 pregnant control subjects.
  
  
  METHODS
  Case and control subjects were matched for body mass index, gestational age, and number of previous pregnancies. A multiple linear regression model with adjustment for the gestational age of the subjects, as the potential confounder of the primary outcomes, was used to evaluate the association between LBP appearance and abdominal muscles thickness of the subjects.
  
  
  METHODS
  The thickness of lateral abdominal muscles was measured by ultrasound with the subject in a hook-lying position on the examination table.
  
  
  RESULTS
  We found that there was no significant difference between pregnant subjects with and without LBP in terms of the thickness of external oblique, internal oblique, and transversus abdominis muscles.
  
  
  CONCLUSIONS
  These findings suggest that other factors rather than the thickness of core stabilizing muscles are influential in the etiology of LBP during pregnancy. We hypothesize that enlargement of uterus during pregnancy might influence the thickness of the lateral abdominal muscles.
authors.affiliation: Sports Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, and Spine Division, Noorafshar Rehabilitation & Sports Medicine Hospital, Tehran, Iran(∗).
authors.forename: Mohsen
authors.initials: M
authors.lastname: Rostami
authors.affiliation: Sports Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, and Spine Division, Noorafshar Rehabilitation & Sports Medicine Hospital, Tehran, Iran(†). Electronic address: normohamadpour@tums.ac.ir.
authors.forename: Pardis
authors.initials: P
authors.lastname: Noormohammadpour
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Science, Tehran, Iran(‡).
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Mansournia
authors.affiliation: Maternal, Fetal and Neonatal Research Center, Tehran University of Medical Sciences, Tehran, Iran(§).
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Hantoushzadeh
authors.affiliation: Sports Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran(¶).
authors.forename: Farzin
authors.initials: F
authors.lastname: Farahbakhsh
authors.affiliation: Sports Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran(‖).
authors.forename: Ruhollah
authors.initials: R
authors.lastname: Nourian
authors.affiliation: Sports Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, and Spine Division, Noorafshar Rehabilitation & Sports Medicine Hospital, Tehran, Iran(∗∗).
authors.forename: Ramin
authors.initials: R
authors.lastname: Kordi
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging*; D000328:Adult; D015992:Body Mass Index; D001837:Body Weights and Measures; D016022:Case-Control Studies; D005260:Female; D020073:Gravidity; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging*; D010147:Pain Measurement; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult