Impact of Exercise on Diastasis Rectus Abdominus

Diastasis recti, is a condition where the linea alba becomes stretched, sometimes lax, and creates distance between the rectus abdominis muscle bellies. It occurs most often during and after pregnancy, abdominal weight gain, and sometimes due to straining while performing heavy lifting. If the linea alba becomes thin enough to tear, the person may experience a hernia. Inter-rectus distance >25mm (~2 finger widths) at one or more locations is considered to be clinically significant for diastasis recti. Pathological diastasis recti is an inter rectus distance widening more than 10mm (~1 finger width) above the umbilicus, 27mm (~2.5 finger widths) at the umbilicus, and 9mm (~1 finger width) below the umbilicus. Normal width of the linea alba in nulliparous women should be less than 15mm at the xiphoid process, 22 mm at 3cm above the umbilicus, and 16mm at 2 cm below umbilicus.

The prevalence of diastasis recti is significant in the postpartum population. Clinically significant diastasis recti is currently thought to be best assessed at 2cm above the umbilicus and 5cm above the umbilicus between 25-41 weeks of pregnancy, and at 6 months postpartum. At 6 months postpartum, the average values for diastasis recti using these measurements were 23mm average at 2cm above the umbilicus (~2.5 finger widths), and 18mm average at 5cm above the umbilicus (~2 finger widths). The measures below the umbilicus were clinically insignificant at 6 months postpartum.

Thed abdominal drawing-in maneuver (transverse abdominis activation) and curl up (rectus abdominis activation) are both exercise maneuvers that have been traditionally taught for diastasis resolution. It was found that curl ups alone narrow the inter-rectus distance but don't achieve tension through the linea alba. Transverse abdominis activation alone tensions the linea alba but doesn't achieve narrowing of the inter-rectus distance. Combined transverse abdominis activation and curl up achieves both narrowing and tension through the linea alba.

The positive correlation between diastasis recti and lumbopelvic pain, incontinence, and pelvic organ prolapse has been shown in recent studies as well. 52% of urogynecological patients had a diastasis recti in one study, and that 66% of those women had a support-related pelvic floor dysfunction (i.e. stress urinary incontinence (UI), fecal incontinence (FI), and/or pelvic organ prolapse (POP)). 45% of women in pregnancy have pelvic girdle pain (PGP), and 25% in the early postpartum period still have PGP. 5-7% of women continue to experience PGP at 12 wks postpartum. 45% of women have urinary incontinence at 7 years postpartum; 27% of those who were initially incontinent in the early postpartum period regained continence, but 31% who were initially continent became incontinent by 7 years postpartum, thus highlighting the need for early intervention of postpartum rehab.

In recent years, research on diastasis recti has become more prevalent. However, the research on diastasis recti recovery and physical therapy treatment programs is limited. Most of the studies thus far have looked at transverse abdominis activation, curl ups, and planks. Effects of strengthening abdominal obliques, hips, pelvic floor, and heavier strengthening of the rectus abdominis done at the same time have not yet been included in these studies.

The aim with this research project is to evaluate the success of diastasis recti closure after a 4-week group exercise class that includes: strengthening of each abdominal muscle group, hip strengthening and stabilization, and pelvic floor activation and cueing during exercises. Success will be evaluated by measuring width and depth of linea alba laxity before and after completion of the 4 sessions as well as other outcome measures such as lumbopelvic pain, pain with intercourse, and incontinence. Intervention will be compared to a control group that participates in an exercise program geared toward general health and wellness.

The goal is to evaluate whether a program incorporating hip, core, and pelvic floor strengthening specifically designed to address the weaknesses common in individuals with diastasis recti is superior to a generalized wellness program in addressing lumbopelvic pain, incontinence, and other pelvic health conditions. If so, this will lay the foundation for a protocol to guide the clinician on safe, yet effective, methods of core strengthening so women are able to transition back into community fitness classes safely and without fear of worsening their diastasis recti.