Effect of pelvic floor and transversus abdominis muscle contraction on inter-rectus distance in postpartum women: a cross-sectional experimental study

Abstract

ObjectivesTo investigate the effect of acute isometric contraction of the pelvic floor muscles (PFM) and transversus abdominis muscle (TrAM) on inter-rectus distance (IRD) from resting values in postpartum women with diastasis rectus abdominis (DRA). DesignCross sectional experimental study. SettingPhysiotherapy clinic. ParticipantsThirty eight postpartum women presenting with DRA of at least two finger widths. MethodsTwo dimensional ultrasound images of IRD were recorded using a linear probe (5 to 10MHz) at rest, during PFM contraction, during TrAM contraction, and during combined PFM and TrAM contraction. IRD data were normally distributed. Main outcome measureChange in IRD. ResultsThere was a significant increase in IRD during PFM and TrAM contraction compared with IRD at rest. At 2cm above the umbilicus, mean PFM was 26.9 [standard deviation (SD) 8.8] mm vs rest 25.7 (SD 8.5) mm {mean difference 1.2 [95% confidence interval (CI) 0.7 to 1.7] mm}; and mean TrAM was 28.4 (SD 9.0) mm vs rest 25.7 (SD 8.5) mm [mean difference 2.8 (95% CI 1.9 to 3.6) mm]. Similarly, 2cm below the umbilicus, mean PFM was 22 (SD 8.3) mm vs rest 21 (SD 7.9) mm [mean difference 0.9 (95% CI 0.4 to 1.6) mm]; and mean TrAM was 23.3 (SD 8.7) mm vs rest 21 (SD 7.9) mm [mean difference 2.3 (95% CI 1.5 to 3.1) mm]. Combined TrAM and PFM contraction measured 2cm above the umbilicus caused the greatest increase in IRD: mean PFM+TrAM 29.6 (SD 9.4) mm vs rest 25.7 (SD 8.5) mm [mean difference 3.9 (95% CI 2.8 to 5.0) mm]. ConclusionBoth PFM and TrAM contraction, and combined PFM and TrAM contraction increased IRD in postpartum women with DRA.