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Mechanisms of pelvic floor muscle function and the effect on the urethra during a cough

By Ruth C. Lovegrove Jones, Qiyu Peng, Maria Stokes, Victor F. Humphrey, Christopher Payne and Christos E. Constantinou


Background: Current measurement tools have difficulty identifying the automatic<br/>physiologic processes maintaining continence, and many questions still remain<br/>about pelvic floor muscle (PFM) function during automatic events.<br/>Objective: To perform a feasibility study to characterise the displacement, velocity,<br/>and acceleration of the PFM and the urethra during a cough.<br/>Design, setting, and participants: A volunteer convenience sample of 23 continent<br/>women and 9 women with stress urinary incontinence (SUI) from the general<br/>community of San Francisco Bay Area was studied.<br/>Measurements: Methods included perineal ultrasound imaging, motion tracking<br/>of the urogenital structures, and digital vaginal examination. Statistical analysis<br/>used one-tailed unpaired student t tests, and Welch’s correction was applied when<br/>variances were unequal.<br/>Results and limitations: The cough reflex activated the PFM of continent women to<br/>compress the urogenital structures towards the pubic symphysis, which was<br/>absent in women with SUI. The maximum accelerations that acted on the PFM<br/>during a cough were generally more similar than the velocities and displacements.<br/>The urethras of women with SUI were exposed to uncontrolled transverse acceleration<br/>and were displaced more than twice as far ( p = 0.0002), with almost twice<br/>the velocity ( p = 0.0015) of the urethras of continent women. Caution regarding<br/>the generalisability of this study is warranted due to the small number of women in<br/>the SUI group and the significant difference in parity between groups.<br/>Conclusions: During a cough, normal PFM function produces timely compression<br/>of the pelvic floor and additional external support to the urethra, reducing displacement,<br/>velocity, and acceleration. In women with SUI, who have weaker<br/>urethral attachments, this shortening contraction does not occur; consequently,<br/>the urethras of women with SUI move further and faster for a longer duratio

Topics: RZ, QP, QM
Year: 2010
OAI identifier:
Provided by: e-Prints Soton

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