A Structural Damage Model for Pelvic Floor Muscles

The childbirth process has been studied continuously and biomechanical models have been seen as quantitative analysis tools. The improvement of such models requires the characterization of the mechanical properties of the tissues involved. During vaginal delivery the muscles undergo large deformations and may suffer damage midway, therefore the definition of a constitutive model including damage process, as presented in this work, becomes critical. The performance of the constitutive model was tested with typical tridimensional simulations to assess the damage evolution. Although the accurate characterization of the mechanical properties is an extremely complex task, the model used seems to capture the typical stress-strain behavior observed in biological soft tissues during both loading-unloading test analysis. With the introduction of damage variables, the model can be also used in damage analysis being the damage evolution well reproduced. Further interpretation requires however extensive model validation using mechanical data on damage development.