Muscle strength measurement of pelvic floor in women by vaginal dynamometer

Abstract

The pelvic floor is made of a mutually connected system that consists of muscles, connecting tissue and nerve components. Damage to any of these elements creates dysfunction which is exerted through stress, urinary incontinence, prolapse of genital organs and faecal incontinence. The primary aim of this study was to present the possibility of objective assessment of pelvic floor muscle force in healthy and sick women using a newly designed instrument, the vaginal dynamometer, as well as to establish the correlation between the values of pelvic floor muscle force obtained by the vaginal dynamometer and digital palpation method. The study included 90 female patients, age 20-58 years. One group of respondents was made of healthy women (who gave birth, and those who have not given birth), while the other one consisted of sick women (who suffered from incontinence or prolapse of genital organs, operated on or not). The pelvic floor muscle strength of every woman was measured with a newly-constructed device for measuring and monitoring of the pelvic floor muscle force in women, the vaginal dynamometer. Then it was compared with the valid clinical digital palpation (palpation with two fingers) based on the scale for measuring muscle contractions with the digital palpation - the digital pelvic assessment rating scale. The vaginal dynamometer consists of a redesigned speculum which is inserted into the vagina and a sensor for measuring the force. Statistically significant linear correlation was found in the values of the measured muscle force with the vaginal dynamometer and ratings produced by digital palpation (r = 0.92; p < 0.001). Mean value of the muscle force of the healthy women measured by the vaginal dynamometer was 1.44 +/- 0.38 daN and that value of the sick women was 0.78 +/- 0.31 daN (t = 8.89 for df = 88; p < 0.001). Mean value of the ratings produced by digital palpation in healthy women was 4.10 (95% of trust limits 3.83-4.37), while the value in sick women was 2.41 (95% of trust limits 2.10-4.16) (Z = -6.38; p < 0.001). The vaginal dynamometer has been presented as an attempt to overcome the limitations of the previously presented techniques for muscle force measurement. The application of the vaginal dynamometer in clinical practice makes objective and numerical assessment of pelvic floor muscle force possible, independent of the subjective assessment of the examiner. The usage of this instrument enables not only the diagnostics of women's pelvic floor muscle problem, but also the objective monitoring of rehabilitation gynaecological medicine results.