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

Objectives To 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). Design Cross sectional experimental study. Setting Physiotherapy clinic. Participants Thirty eight postpartum women presenting with DRA of at least two finger widths. Methods Two dimensional ultrasound images of IRD were recorded using a linear probe (5 to 10 MHz) at rest, during PFM contraction, during TrAM contraction, and during combined PFM and TrAM contraction. IRD data were normally distributed. Main outcome measure Change in IRD. Results There was a significant increase in IRD during PFM and TrAM contraction compared with IRD at rest. At 2 cm 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, 2 cm 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 2 cm 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]. Conclusion Both PFM and TrAM contraction, and combined PFM and TrAM contraction increased IRD in postpartum women with DRA. (C) 2018 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.