Assessment of pelvic floor and abdominal muscles three months postpartum: A reliability study

Abstract

Background Pregnancy and childbirth often result in alterations of core muscles, and women may require postpartum assessment of pelvic floor muscle function and abdominal wall changes, e.g. diastasis recti abdominis (DRA). However, there is currently no gold standard for postpartum assessment of these muscles´ function. Here we aimed to evaluate the reliability of clinically applicable methods for assessing pelvic floor muscles and DRA after pregnancy. Methods We recruited 222 postpartum women from Swedish antenatal and childbirth centers, and via social media. Pelvic floor and DRA assessment were performed via observation and palpation at three rehabilitation centers in Sweden. At each center, two independent physiotherapists performed the assessments in random order. Results Assessment of the maximal voluntary contraction and pelvic floor muscle endurance revealed kappa values ranging from 0.49–0.69. Assessments of voluntary contraction by observation, involuntary contraction, and voluntary relaxation yielded inconsistent results, with slight-to-moderate weighted kappa values ranging from 0.10–0.51. DRA assessment by caliper yielded ICC values of 0.73–0.83 after physiotherapists underwent 2 months of training in applying this assessment method. The standard error of measurements for this method was about 4 mm, and the minimal detectable change was 12 mm. Assessments of DRA depth and bulging showed moderate kappa values of 0.43–0.51, with reservation for some inconsistency between the centers. Conclusions Palpation of maximal voluntary contraction and pelvic floor muscle endurance are reliable postpartum assessment methods. With some experience and training, a caliper is a reliable instrument for assessing the postpartum DRA width. Additional research is needed to identify a reliable assessment method for pelvic floor muscle functions other than voluntary contraction, and for DRA depth and bulging.