Stress urinary incontinence (SUI) occurs due to anatomic and/or neurologic 
factors involving connective tissues, muscles and nerves. Although SUI is more 
common in post-menopausal and multiparous women, studies have also shown a high 
prevalence of SUI in young, physically fit female athletes. With a goal toward 
dynamic subject-specific mechanical characterization of the interaction between 
anatomical structures during physical activities that elicit SUI in females 
during physical or daily activities, a computer aided design (CAD)-based 
computer model of the female pelvis has been developed to test the feasibility 
of the computer modeling approach in understanding the measurable differences 
between stress-continent and stress-incontinent women. In the present study, a 
fluid-structure interaction analysis was conducted by using the finite element 
(FE) analysis technique based on the CAD-based computer model of the female 
pelvis to investigate the urine leakage in females during jumping. To the best 
of our knowledge, this is the first application of a fluid-structure interaction 
FE analysis approach in understanding the mechanisms of SUI in females. Through 
a series of computer simulations, the effects of varying impact forces 
determined by jumping height and bladder volume were investigated. The dynamic 
computer simulation results revealed that jumping heights have a significant 
influence on the volume of urine leakage caused by the landing impact of 
jumping. Bladder volume did not have a significant influence on leakage when the 
jumping heights were smaller than 1 ft, which indicates that normal walking 
(corresponds to a jumping height smaller than 0.1 ft) is not the primary cause 
of urine leakage for healthy females. The computer simulation results also 
showed that the deformation difference between the anterior and posterior 
portion of the female pelvis causes opening of the urethra and resultant urine 
leakage. The present study demonstrates the feasibility of using a computer 
modeling approach to study female SUI during physical and daily activities.