title: Abdominal exercises affect inter-rectus distance in postpartum women: a two-dimensional ultrasound study.
abstract: OBJECTIVE
  To compare inter-rectus distance (IRD) at rest between women who had a vaginal delivery with women who had a caesarean section, and to describe the effect of different abdominal exercises on IRD.
  
  
  METHODS
  Physiotherapy practice.
  
  
  METHODS
  Cross-sectional experimental study.
  
  
  METHODS
  Thirty-eight postpartum primiparous mothers with a singleton baby (vaginal delivery: n=23; caesarean section: n=15).
  
  
  METHODS
  Two-dimensional ultrasound images from the abdominal wall were recorded at rest and at the end position of abdominal crunch, drawing-in and drawing-in+abdominal crunch exercises. IRD measurements at rest, above and below the umbilicus, were compared between the two groups (vaginal delivery and caesarean section). IRD was also measured above and below the umbilicus during three abdominal exercises in both groups.
  
  
  METHODS
  IRD 2 cm above and below the umbilicus.
  
  
  RESULTS
  No significant differences in IRD, either above or below the umbilicus, were found between the vaginal delivery and caesarean section groups. IRD above the umbilicus was significantly reduced during abdominal crunch exercises compared with at rest {mean 21.7 [standard deviation (SD) 7.6]mm vs 25.9 (SD 9.0) mm; mean difference 4.2 mm; 95% confidence interval (CI) 0.5 to 7.9}. IRD below the umbilicus was significantly greater during drawing-in exercises compared with at rest [16.0 (SD 8.1) mm vs 11.4 (SD 4.9) mm; mean difference 4.5 mm; 95% CI 1.6 to 7.4].
  
  
  CONCLUSIONS
  In contrast to existing recommendations for abdominal strength training among postpartum women, this study found that abdominal crunch exercises reduced IRD, and drawing-in exercises were ineffective for reducing IRD. Further basic studies and randomised controlled trials are warranted to explore the effect of abdominal training on IRD.
authors.affiliation: Department of Physiotherapy, Escola Superior de Saúde do Alcoitão, Alcoitão, Portugal.
authors.forename: M F
authors.initials: MF
authors.lastname: Sancho
authors.affiliation: Faculdade de Motricidade Humana, Universidade de Lisboa, CIPER, LBMF, Lisbon, Portugal. Electronic address: gpascoal@fmh.ulisboa.pt.
authors.forename: A G
authors.initials: AG
authors.lastname: Pascoal
authors.affiliation: Faculdade de Motricidade Humana, Universidade de Lisboa, CIPER, LBMF, Lisbon, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Mota
authors.affiliation: Department of Sports Medicine, Norwegian School of Sports Sciences, Oslo, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Bø
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging / Q000502:physiology*; D000328:Adult; D002585:Cesarean Section; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric / Q000009:adverse effects*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D049590:Postpartum Period; D011247:Pregnancy / Q000502:physiology*; D014463:Ultrasonography
keywords: Caesarean section; Diastasis recti; Exercise; Inter-rectus distance; Postpartum Women; Ultrasound