Biomechanics of the female pelvic floor: a prospective trail of the alteration of force–displacement-vectors in parous and nulliparous women

Objective We hypothesize that the holistic and multiplanar depiction of pelvic floor structures by dynamic MRI is of particular value in rendering information about the extent of functional changes that can lead to pelvic floor dysfunction. Methods 134 women were prospectively included for assessment of their pelvic floor function. Results Study groups differed significantly in the direction of their force–displacement-vectors. A shift from ventral to dorsal is present depending on parity, mode of delivery and age. Maternal age and body height correlated to the force–displacement-vector, whereas maternal weight did not. Pressing direction proved to be dependent on the inclination of the pelvis and the aperture of the levator hiatus while remaining independent from the aperture of the abdominal wall. Conclusion Biomechanical data interpretation uncovered the pathogenetic relevance of progressive retroflection of the force–displacement-vector. This is responsible for the onset of a vicious cycle of trauma-related force deflection perpetuating pelvic floor traumatization.