The Pelvic Floor

Contents

1. A sling across the pelvic outlet
2. Muscle, fascia and ligament
3. What the pelvic floor does
4. How pelvic floor disorders are counted
5. Risk across a lifetime
6. Treatment from habits to surgery

Pelvic reconstruction and bladder suspension procedures belong to Candace Cooley’s surgical experience, and each is a repair of the same structure: the floor of muscle and connective tissue that closes the bottom of the pelvis. How often that structure falters was not measured nationally until 2008, when researchers in the NIH Pelvic Floor Disorders Network added questions to a federal health survey and reported that 23.7 percent of the women who answered had symptoms of at least one pelvic floor disorder.⁴ The figure covered 1,961 women aged 20 and older who were not pregnant, and the authors noted that it counted moderate and severe symptoms only.⁴

A sling across the pelvic outlet

The bony pelvis is a ring, and the pelvic floor fills its lower opening. A pelvic floor physical therapist interviewed by NPR described it as a basket of muscles running from the pubic bone at the front to the sacrum at the back and across from side to side.¹ The NICHD release on the 2008 study used a different image, a sling of muscles and ligaments that holds the bladder, uterus, bowel and rectum in their places.⁴ Both pictures point at the same job. The organs above rest on this layer, and the urethra, vagina and anus pass through it.

Muscle, fascia and ligament

Support comes from more than muscle. A lecture on prolapse prepared for medical students at Loyola University’s Stritch School of Medicine lists three partners: the levator muscles, the fasciae of the urogenital diaphragm and the endopelvic layer, and two sets of ligaments, the cardinal and the uterosacral.⁵ The same lecture records a shift in thinking about failure. Where earlier accounts pictured tissue gradually giving way, more recent work traces many failures to discrete tears, and each tear leaves a defect a clinician can locate by examining the woman.⁵ Surgeons describe prolapse by which organ descends, whether the uterus, the bladder (a cystocele), the rectum (a rectocele) or the small bowel (an enterocele).⁵

Figure

Pelvic floor disorders rise with age

• Ages 20 to 399.7
• Ages 40 to 5926.5
• Ages 60 to 7936.8
• 80 and older49.7

percent

What the pelvic floor does

The obvious task is holding. The FDA Office of Women’s Health adds that these muscles keep bladder and bowel control and help maintain sexual function.³ Continence depends on teamwork. A bladder control booklet from the National Institute of Diabetes and Digestive and Kidney Diseases names the pelvic floor muscles, the ring shaped sphincters around the urethra, the bladder wall itself, the nerves and the hormones that keep the lining healthy, and notes that trouble can begin when any one of them stops working properly.⁶

The floor also moves with the breath. As the diaphragm flattens on an inhale, the pelvic floor softens and lowers, then rises again with the exhale, and it works alongside the abdominal muscles to steady the spine.¹ An NPR Life Kit summary of the same interview notes that emptying the bladder is the job of the bladder muscle, and that it works best when the pelvic floor is relaxed rather than bearing down.²

Figure

The parts that keep the bladder under control

1. 01
   Pelvic floor musclesHold the bladder in its place in the pelvis.
2. 02
   Sphincter musclesRing shaped muscles keep the urethra closed until it is time to empty.
3. 03
   Bladder muscleRelaxes while it fills and squeezes when it is time to urinate.
4. 04
   Nerves and brainSignals travel both ways, reporting a full bladder and telling it when to empty.
5. 05
   HormonesHelp keep the lining of the bladder and urethra healthy.

How pelvic floor disorders are counted

Three conditions make up the core group: leakage of urine, leakage of stool and pelvic organ prolapse.⁴ In the national survey, 15.7 percent of women reported urinary incontinence, 9.0 percent fecal incontinence and 2.9 percent symptoms of prolapse.⁴ The share climbed with age, from under one in ten women aged 20 to 39 to nearly half of those over 80, and it climbed with the number of births.⁴

Counting depends on how the question is asked. For prolapse, the Loyola lecture cites a symptom rate of 3 to 6 percent against 41 to 50 percent when support is measured on examination, which means most women with a measurable defect feel nothing from it.⁵ The FDA lists pelvic pain alongside the core three, including pain in the vulva, painful sex and involuntary spasm of the vagina.³

Figure

Three common pelvic floor disorders

	What gives way	How it tends to show
Urinary incontinence	Support and closure of the bladder outlet	Leaks with a cough, laugh or sneeze, or with a sudden urge
Fecal incontinence	Muscles that control the release of stool	Leakage of stool or trouble holding gas
Pelvic organ prolapse	Support for the uterus, bladder or bowel	Heaviness or a bulge felt at the vaginal opening

Risk across a lifetime

The FDA groups the causes into a few families.³ Pregnancy and vaginal birth change the nerves, muscles and connective tissue of the floor, more so with each additional child. Steady pressure from excess weight, chronic constipation, heavy lifting or a long cough adds load. Muscles weaken with age and around menopause. Some women inherit connective tissue that is less strong, and a history of hysterectomy or earlier prolapse repair raises the risk as well.³ The entry on pelvic organ prolapse follows the most visible of these failures, and the one on stress urinary incontinence follows the most common.

Treatment from habits to surgery

Care runs along a ladder that the FDA describes as lifestyle measures first, then nonsurgical treatment, then surgery, alone or in combination.³ The early rungs include a high fiber diet to avoid straining, weight loss to ease pressure and bladder training on a set schedule. Nonsurgical options add pelvic floor exercises and myofascial release, medicine for some bladder and bowel problems, and a pessary, a removable support worn in the vagina.³ Surgery is reserved for prolapse that impairs quality of life and for stress leakage that other measures have not helped; for the latter, the NIDDK booklet describes a sling that lifts and supports the bladder neck and urethra.⁶ Pelvic floor physical therapy sits in the middle of that ladder and has an entry of its own.

Two parts of this subject rest on the firmest evidence. The prevalence figures come from a nationally representative sample and show a steady rise with age and with births.⁴ For stress leakage, the NIDDK booklet reports that women who practice pelvic muscle exercises usually notice fewer leaks after about six to eight weeks.⁶ Links between the pelvic floor and conditions such as irritable bowel syndrome or lower back pain remain under study.³ Applying these findings to an individual woman takes an examination no survey can provide, which is the work of her own clinician.