Women with incorrect pelvic floor statics: a biomechanical answer to the mechanical loading of the vagina-endopelvic fascia complex.

OBJECTIVE: This work focuses on finding method for detecting the elementary mechanical characteristics of the vagina-endopelvic fascia complex, aimed at providing results for use in optimizing solutions for stability defects of the pelvic floor.

MATERIALS AND METHODS: Two experiments have already been carried out that have enabled monitoring of the reaction of tissue complex samples to a selected load. The elastic properties of samples under a simple pull load were evaluated. The monitored property in the first experiment was the maximum reference tension at the moment of rupture of the sample in relation to the non-deformed section. We evaluated data from measurements on 11 samples within the scope of the first experiment. For data processing from the second experiment we used a linear-elastic model of the sample, formed by parallel connection of basic mechanical elements - springs - that represented the endopelvic fascia and the vaginal wall. The relevant rigidities were used for a description of their properties. Five samples were used for this experiment.

RESULTS: An important discovery was that the endopelvic fascia tears apart after a longer period of time than the vaginal wall during the pull test. The results show considerable variability among individuals, but the pattern of curves is similar in all test cases. In all measured data we found a rigidity increase zone, a maximum rigidity zone and a gradual rigidity decrease zone before terminal damage in the response.

CONCLUSIONS: The results presented here show quite broad interindividual variability of the mechanical properties of the vaginal wall-endopelvic fascia complex. It appears that the mechanical properties of the tissue complex change with number of pregnancies, and are affected by diseases, by physical load or by the presence of other factors, e.g. obesity.