Accuracy of a modified CMT+ for assessing pelvic floor muscle contraction in pregnancy

Abstract

Objective: The ability to locate pelvic floor muscles (PFM) is essential for the effectiveness of pelvic floor muscle training programs. The aim of this study was to investigate the accuracy of a modified coccygeal movement test that incorporates an objective assessment of abdominal muscle co-activation (CMT⁺) (Index test) compared to transabdominal ultrasound (TAU) scanning (Gold standard) in diagnosing accurate PFM contraction. Methods: Pregnant women attending the hospital for a routine in the middle 2^nd trimester scan who are able to understand the study rationale and information were considered eligible for inclusion. TAUs were performed by one out of two trained operators. CMT⁺ was performed by an experienced physiotherapist. The CMT⁺ assessor and participants were blind to the TAU result. Results: A total of 117 participants were recruited into the study with a mean BMI of 30.86 kg/m² (4.5) and 23.16 kg/m² (3.7), resp. CMT⁺ (Index test) correctly identified 5 out of the 9 participants who were not able to contract and 107 out of the 108 who were able to contract their PFM resp. (sensitivity = 55.6%, specificity = 99.1%, positive predictive value = 83.3% and negative predictive value = 96.4%; LR+ = 60 and LR– = 0.45). Conclusion: CMT⁺ is an easy to perform test with high specificity and negative predictive value that has the additional benefit of assessing any concomitant abdominal muscle co-activation. Therefore, CMT⁺ is a potentially useful initial screening test to identify those who cannot perform a correct pelvic floor muscle contraction, and would benefit from specialized assessment and structured training.