Stress urinary incontinence is a significant problem in young female athletes, but the pathophysiology remains unclear because of the limited knowledge of the pelvic floor support function and limited capability of currently available assessment tools. The aim of our study is to develop an advanced computer modeling tool to better understand the dynamics of the internal pelvic floor during highly transient athletic activities.
Apelvic model was developed based on high-resolution MRI scans of a healthy nulliparous young female. A jump-landing process was simulated using realistic boundary conditions captured from jumping experiments. Hypothesized alterations of the function of pelvic floor muscles were simulated by weakening or strengthening the levator ani muscle stiffness at different levels. Intra-abdominal pressures and corresponding deformations of pelvic floor structures were monitored at different levels of weakness or enhancement.
Results show that pelvic floor deformations generated during a jump-landing process differed greatly from those seen in a Valsalva maneuver which is commonly used for diagnosis in clinic. The urethral mobility was only slightly influenced by the alterations of the levator ani muscle stiffness. Implications for risk factors and treatment strategies were also discussed.
Results suggest that clinical diagnosis should make allowances for observed differences in pelvic floor deformations between a Valsalva maneuver and a jump-landing process to ensure accuracy. Urethral hypermobility may be a less contributing factor than the intrinsic sphincteric closure system to the incontinence of young female athletes.
Clinical biomechanics (Bristol, Avon). 2016 Jan 18 [Epub ahead of print]
Nicholas Dias, Yun Peng, Rose Khavari, Nissrine A Nakib, Robert M Sweet, Gerald W Timm, Arthur G Erdman, Timothy B Boone, Yingchun Zhang
Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA. Electronic address: ., Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA. Electronic address: ., Department of Urology, Houston Methodist Hospital and Research Institute, 6565 Fannin St, Suite 2100, Houston, TX 77030-2703, USA. Electronic address: ., Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA. Electronic address: ., Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA. Electronic address: ., Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA. Electronic address: ., Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455-0341, USA. Electronic address: ., Department of Urology, Houston Methodist Hospital and Research Institute, 6565 Fannin St, Suite 2100, Houston, TX 77030-2703, USA. Electronic address: ., Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA. Electronic address: .