Pelvic floor muscle exercise for the treatment of female stress urinary incontinence: I. Reliability of vaginal pressure measurements of pelvic floor muscle strength

The reliability of measurements of pelvic floor muscle strength using a vaginal balloon catheter connected to a pressure transducer was tested in 28 healthy women, mean age 32.3 years (21–50). Fourteen women (group 1) performed three pelvic floor muscle contractions in three series with reinstallation of the balloon catheter to the same vaginal position between each series. Additionally, retest was done after a period of 2 weeks. Reproducibility of the results was tested in another similar group of 14 women (group 2) who did a 1 day test. In the first group the maximum contraction value (resting pressure not included) varied from 5 to 40 cm H2O. However, the median difference value of the three series tested on two different days was only 3, 1, and 1 cm H2O, respectively. The two groups of women demonstrated similar values of vaginal pressure measurements. Thus, a balloon with a given vaginal position for measurements of pelvic floor muscle strength gives reliable pressure recordings.