title: The effect of abdominal and pelvic floor muscle activation patterns on urethral pressure.
abstract: OBJECTIVE
  Urethral pressure increases during voluntary pelvic floor (PF) muscle contractions in healthy women. As PF and abdominal muscle activity is coordinated, this study aimed to determine whether specific abdominal muscle actions also change urethral pressure.
  
  
  METHODS
  Urethral pressures were measured in seven healthy women during lower abdominal in-drawing, abdominal bulging and PF muscle contractions, with the bladder empty and filled to 250 ml. A repeated measures multiple analysis of variance compared vesical, rectal and urethral pressure changes between bladder volumes and the three tasks.
  
  
  RESULTS
  Urethral pressures increased by a similar amount during PF muscle contractions and abdominal in-drawing (p = 0.94) and did not differ between bladder status. During abdominal bulging, urethral pressures decreased by 12.6 (18.2) cmH2O (full bladder) and 18.1 (11.5) cmH2O (empty bladder) and were different from the other two manoeuvres (p < 0.001).
  
  
  CONCLUSIONS
  This study shows that specific abdominal actions are associated with increased or decreased urethral pressures, consistent with strategies for continence and voiding.
authors.affiliation: School of Health and Rehabilitation Sciences, National Health and Medical Research Council Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, The University of Queensland, Brisbane, QLD, 4072, Australia. rsapsford@ozemail.com.au
authors.forename: Ruth R
authors.initials: RR
authors.lastname: Sapsford
authors.forename: Barton
authors.initials: B
authors.lastname: Clarke
authors.forename: Paul W
authors.initials: PW
authors.lastname: Hodges
mesh_terms: D000009:Abdominal Muscles / Q000502:physiology*; D000328:Adult; D005260:Female; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D017773:Pelvic Floor / Q000502:physiology*; D011312:Pressure; D014521:Urethra / Q000502:physiology*; D001743:Urinary Bladder / Q000502:physiology; D014554:Urination / Q000502:physiology; D014563:Urodynamics / Q000502:physiology