Abstract
The aim of the study was to identify the striated muscle forces hypothesized to assist bladder neck opening and closure in females. Cadaveric dissection was used to identify the levator plate (LP), the anterior portion of pubococcygeus muscle (PCM), the longitudinal muscle of the anus (LMA), and their relation to the bladder, vagina and rectum. X-ray video recordings were made during coughing, straining, squeezing and micturition in a group of 20 incontinent patients and 4 controls, along with surface EMG, urethral pressure and digital palpation studies. During effort, urethral closure appeared to be activated by a forward muscle force corresponding to PCM, and bladder neck closure by backward muscle forces corresponding to LP and LMA. During micturition the PCM force appeared to relax, allowing LP and LMA to pull open the outflow tract. The data appear to support the hypothesis of specific directional muscle forces stretching the vagina to assist bladder neck opening and closure.
Similar content being viewed by others
References
Blaivas JG. The neurophysiology of micturition: a clinical study of 550 patients.J Urol 1982;127:958–962
Enhorning G. Simultaneous recording of intravesical and intraurethral pressure.Acta Chir Scand 1961;(Suppl)27:61–68
De Lancey JOL. Structural support of the urethra as it relates to stress incontinence: the hammock hypothesis.Am J Obstet Gynecol 1994;170:1713–1723
Shafik A. Micturition and urinary continence: new concepts.Int Urogynecol J 1992;3:168–175
Petros PE, Ulmsten U. An integral theory of female urinary incontinence.Acta Obstet Gynecol Scand (1990); (Suppl 153) 69:1–79
Petros P, Ulmsten U. An integral theory and its method for the diagnosis and management of female urinary incontinence.Scand J Urol Nephrol 1993; (Suppl 153) 27: Part 1, 1–93
Berglas B, Rubin IC. Study of the supportive structures of the uterus by levator myography.Surg Gynecol Obstet 1953;97:677–692
Courtney H. Anatomy of the pelvic diaphragm and ano-rectal musculature as related to sphincter preservation in ano-rectal surgery.Am J Surg 1950;79:155–173
Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. II anatomy of the levator ani muscle with special reference to puborectalis.Invest Urol 1975;13:175–182
Zacharin RF. A suspensory mechanism of the female urethra.J Anat 1963;97:423–427
Petros PE, Ulmsten U. Urethral pressure increase on effort originates from within the urethra, and continence from musculovaginal closure.Neurourol Urodyn 1995;14:337–350
Christensen LL, Djurhuus JC, Constantinou CE. Imaging of pelvic floor contractions using MRI.Neurourol Urodyn 1995;14:209–216
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Papa Petros, P.E., Ulmsten, U. Role of the pelvic floor in bladder neck opening and closure I: Muscle forces. Int Urogynecol J 8, 74–80 (1997). https://doi.org/10.1007/BF02764822
Issue Date:
DOI: https://doi.org/10.1007/BF02764822