Effectiveness of Early Postpartum Rectus Abdominis versus Transversus Abdominis Training in Patients with Diastasis of the Rectus Abdominis Muscles: A Pilot Randomized Controlled Trial

Abstract

Purpose: To determine feasibility of a randomized controlled trial (RCT) comparing postpartum rectus abdominis training with transversus abdominis training in reducing the inter-recti distance in patients with diastasis of the rectus abdominis muscles (DRAM). Method: A pilot, randomized controlled trial with longitudinal assessment following vaginal delivery at 6 and 12 weeks postpartum was completed. Forty-four women with DRAM (inter-recti distance of ≥ 30mm as measured by digital calipers) were recruited from a regional public hospital in Australia. The standard treatment group ( n = 21) was provided with a 5-second transversus abdominis activation exercise in crook lying. The experimental group ( n = 23) was provided with a 1-second rectus abdominis crunch exercise. Dosage was between 1–10 repetitions at baseline and between 1–20 at 6 weeks, twice a day, at least 5 days per week, prescribed depending on individual participant ability. The primary outcome measure was inter-recti distance. Feasibility measures were recruitment rate, loss to follow-up, adverse events, and exercise adherence. Results: The rectus abdominis group achieved greater reduction of the inter-recti distance at 6 weeks (at and below the umbilicus) and 12 weeks (above, below, and at the umbilicus). Recruitment rate was acceptable (45%) and there were no adverse events, but loss to follow-up was high due to COVID-19 impacts and participants did not return exercise adherence diaries. Conclusion: Prescription of rectus abdominis exercise during the early postpartum period following vaginal delivery resulted in a greater reduction of the inter-recti distance at 6 and 12 weeks when compared with transversus abdominis exercise. This pilot trial was impacted by high loss to follow up due to COVID-19 restrictions, but feasibility was otherwise acceptable. The findings of the study will inform future fully powered trials comparing these two exercise types in postpartum women with DRAM.