Comparison of Trunk Muscle Function Between Women With and Without Diastasis Recti Abdominis at 1 Year Postpartum

Background. A separation of the abdominal muscles at the linea alba, known as diastasis recti abdominis (DRA), can occur after childbirth. However, the impact of DRA on abdominal muscle function is not clear. Objective. The objective was to determine if differences exist in trunk muscle function and self-reported pain and low back dysfunction between women with and without DRA at 12 to 14 months postpartum and if differences that emerge from the data are associated with the magnitude of the interrectus distance (IRD). Design. This study was a prospective, observational, case-control study. Methods. Women with (IRD >= 2.2 cm; n = 18) and without DRA (IRD <2.2 cm; n = 22) participated. Maximal trunk flexion, extension, and rotation torque-generating capacity (Newton-meters), the Sit-Up test (0 to 3 points), and the Sitting-Rising Test (0 to 10 points), and trunk flexion, extension, and lateral flexion endurance (seconds) were measured. Pain and disability were assessed using numerical pain rating scales (0 to 100) and the Roland Morris Low Back Pain Questionnaire (0 to 24 points). Women were compared using independent t tests and Mann-Whitney U Tests. Pearson product-moment and Spearman rank correlation coefficients were used to determine associations; alpha = .05 was used for all tests. Results. Women with DRA demonstrated significantly lower trunk muscle rotation torque and scored lower on the sit-up test than those without DRA. IRD was negatively correlated with both trunk rotation torque (rho = -0.367) and sit-up test score (rho = -0.514). Limitations. The results of this study should not be generalized to women who present with moderate-to-severe IRDs or to multiparous women. Conclusion. The presence of DRA in primiparous women at 1 year postpartum is associated with trunk rotation strength and ability to perform a sit-up.