Purpose: 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.