Coccygeal Movement Test: An Objective, Non-Invasive Test for Localization of the Pelvic Floor Muscles in Healthy Women

OBJECTIVE: To evaluate the use of palpation of the coccyx (the coccygeal movement test, CMT) as a possible objective screening tool for the assessment of adequate localization of the pelvic floor muscles (PFMs). SUBJECTS AND METHODS: Twenty-four healthy female volunteers, known to be able to locate their PFMs, were given instructions (allocated at random) to perform a ‘correct contraction’, ‘straining’ or ‘nothing’ when examined by six independent assessors using the CMT. The assessors were blinded to the instructions and to the test results recorded by other assessors. Data were available for 137 observations, and these were dichotomized into either ‘able to contract’ (‘correct contraction’) or ‘not able to contract’ (‘straining’ or ‘nothing’). This information was used to calculate the sensitivity, specificity and positive and negative predictive values for the CMT. RESULTS: The CMT correctly identified 56/58 observations when women did not perform the contraction of the PFMs compared to 61/79 observations when they did. Hence, the sensitivity and specificity were 97 and 77%, respectively. CONCLUSION: This study showed that the CMT was a useful test to identify women who were able to localize their PFMs compared to those who were not, making it a potentially useful initial screening test in structured training programmes for the PFMs.