To build the mechanical model of the m. levator ani to analyze its stress distribution in pathological state, and provide reference to further know pelvic floor dysfunction(PFD) in terms of mechanics.

Based on magnetic resonance imaging (MRI) of the pelvic floor, to reconstruct the geometric structure of the m. levator ani using the medical imaging software MIMICS and to simulate the stress distribution of the m. levator ani using the finite element method.

For both the viscera organs prolapse and the stress urinary incontinence the maximum stress position were same but the magnitude was difference in the m. levator ani. The maximum stress in the m. levator ani was more higher between the viscera organs prolapse and the type I stress urinary incontinence, but it was lowest for the type Ⅲ stress urinary incontinence among type Ⅰ to Ⅲ stress urinary incontinence and the viscera organs prolapse.

High intra-abdominal pressure will all produce high stress in the m. levator ani for the four pathological states, thus it is easy to damage the m. levator ani. The result will provide some theory reference for preventing PFD in clinic.