Relationship between area and moment of inertia with pubovisceral muscle displacement by biomechanical models

Changes in the morphology of the pelvic floor muscles (PFM) or in their attachment points can cause functional weakness, especially when during effort. When there is the need to counteract the increase in intra-abdominal pressure, urinary leakage may occur, which may in turn be related to the reduction of Moment of Inertia (MOI). We aimed to test the relation between muscle morphology, MOI and muscle displacement during computational simulation of valsalva maneuver. For that purpose, axial MRI images from five athletes were acquired. Measures of muscle thickness and area were taken, and the MOI and cross-sectional area were calculated using segmentation splines from the Inventor^® software. Additionally, biomechanical models were through numerical simulation of valsalva maneuver using the Abaqus^® software. The results showed an association between MOI and muscle displacement (p=0.037; r=-0.900) and thickness (p=0.037; r=0.900). Muscle area showed no significative association with the displacement during valsalva maneuver.