Pelvic floor
Encyclopedia
The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani
, the coccygeus, and associated connective tissue
which span the area underneath the pelvis
. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the parietal pelvic fascia on their upper and lower aspects. The pelvic floor separates the pelvic cavity
above from the perineal region (including perineum
) below.
The right and left levator ani lie almost horizontally in the floor of the pelvis, separated by a narrow gap that transmits the urethra, vagina, and anal canal. The levator ani is usually considered in three parts: pubococcygeus, puborectalis, and iliococcygeus. The pubococcygeus, the main part of the levator, runs backward from the body of the pubis toward the coccyx and may be damaged during parturition. Some fibers are inserted into the prostate, urethra, and vagina. The right and left puborectalis unite behind the anorectal junction to form a muscular sling. Some regard them as a part of the sphincter ani externus. The iliococcygeus, the most posterior part of the levator ani, is often poorly developed.
The coccygeus, situated behind the levator ani and frequently tendinous as much as muscular, extends from the ischial spine to the lateral margin of the sacrum and coccyx.
The pelvic cavity
of the true pelvis has the pelvic floor as its inferior border (and the pelvic brim
as its superior border). The perineum
has the pelvic floor as its superior border.
Some sources do not consider "pelvic floor" and "pelvic diaphragm" to be identical, with the "diaphragm" consisting of only the levator ani and coccygeus, while the "floor" also includes the perineal membrane
and deep perineal pouch
. However, other sources include the fascia
as part of the diaphragm. In practice, the two terms are often used interchangeably.
Posteriorly, the pelvic floor extends into the anal triangle
.
, intestine
s, the uterus
(in females), and in maintenance of continence as part of the urinary
and anal
sphincters. It facilitates birth by resisting the descent of the presenting part, causing the fetus to rotate forwards to navigate through the pelvic girdle.
. There is some evidence that these muscles may also be damaged during a hysterectomy
. Pelvic surgery using the "perineal approach" (between the anus and coccyx) is an established cause of damage to the pelvic floor. This surgery includes coccygectomy
.
In female high-level athletes, perineal trauma is rare and is associated with certain sports (each with a distinct type of trauma): water-skiing, bicycle racing
, and equestrian sports.
Damage to the pelvic floor not only contributes to urinary incontinence but can lead to pelvic organ prolapse
. Pelvic organ prolapse occurs in women when pelvic organs (e.g. the vagina, bladder, rectum, or uterus) protrude into or outside of the vagina. The causes of pelvic organ prolapse are not unlike those that also contribute to urinary incontinence. These include inappropriate (asymmetrical, excessive, insufficient) muscle tone and asymmetries caused by trauma to the pelvis. Age, pregnancy, family history, and hormonal status all contribute to the development of pelvic organ prolapse. The vagina is suspended by attachments to the perineum, pelvic side wall and sacrum via attachments that include collagen, elastin, and smooth muscle. Surgery can be performed to repair pelvic floor muscles. The pelvic floor muscles can be strengthened with Kegel exercises
.
Disorders of the posterior pelvic floor include rectal prolapse
, rectocele
, perineal hernia
, and a number of functional disorders including anismus
. Constipation
due to any of these disorders is called "functional constipation" and is identifiable by clinical diagnostic criteria.
Pelvic floor exercise (PFE), also known as Kegel exercises, may improve the tone and function of the pelvic floor muscles, which is of particular benefit for women (and less commonly men) who experience stress urinary incontinence. However, compliance with PFE programs often is poor, PFE generally is ineffective for urinary incontinence unless performed with biofeedback
and trained supervision, and in severe cases it may have no benefit. Pelvic floor muscle tone may be estimated using a perineometer
, which measures the pressure within the vagina. Medication may also be used to improve continence. In severe cases, surgery may be used to repair or even to reconstruct the pelvic floor. It has been reported that patients who have overly-toned musculature may suffer from inability to relax the pelvic floor muscles - in effect, Kegel exercises would only exacerbate the problem. http://www.massagetoday.com/mpacms/mt/article.php?id=13515
Perineology
or pelviperineology is a speciality dealing with the functional troubles of the three axis (urological, gynaecological and coloproctological) of the pelvic floor.
Levator ani
The levator ani is a broad, thin muscle, situated on the side of the pelvis.It is attached to the inner surface of the side of the lesser pelvis, and unites with its fellow of the opposite side to form the greater part of the floor of the pelvic cavity....
, the coccygeus, and associated connective tissue
Connective tissue
"Connective tissue" is a fibrous tissue. It is one of the four traditional classes of tissues . Connective Tissue is found throughout the body.In fact the whole framework of the skeleton and the different specialized connective tissues from the crown of the head to the toes determine the form of...
which span the area underneath the pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the parietal pelvic fascia on their upper and lower aspects. The pelvic floor separates the pelvic cavity
Pelvic cavity
-External links:* * *...
above from the perineal region (including perineum
Perineum
In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
) below.
The right and left levator ani lie almost horizontally in the floor of the pelvis, separated by a narrow gap that transmits the urethra, vagina, and anal canal. The levator ani is usually considered in three parts: pubococcygeus, puborectalis, and iliococcygeus. The pubococcygeus, the main part of the levator, runs backward from the body of the pubis toward the coccyx and may be damaged during parturition. Some fibers are inserted into the prostate, urethra, and vagina. The right and left puborectalis unite behind the anorectal junction to form a muscular sling. Some regard them as a part of the sphincter ani externus. The iliococcygeus, the most posterior part of the levator ani, is often poorly developed.
The coccygeus, situated behind the levator ani and frequently tendinous as much as muscular, extends from the ischial spine to the lateral margin of the sacrum and coccyx.
The pelvic cavity
Pelvic cavity
-External links:* * *...
of the true pelvis has the pelvic floor as its inferior border (and the pelvic brim
Pelvic brim
The pelvic brim is the edge of the pelvic inlet. It is an approximately apple-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis....
as its superior border). The perineum
Perineum
In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
has the pelvic floor as its superior border.
Some sources do not consider "pelvic floor" and "pelvic diaphragm" to be identical, with the "diaphragm" consisting of only the levator ani and coccygeus, while the "floor" also includes the perineal membrane
Perineal membrane
The perineal membrane is an anatomical term for a fibrous membrane in the perineum. The term "inferior fascia of urogenital diaphragm", used in older texts, is considered equivalent to the perineal membrane....
and deep perineal pouch
Deep perineal pouch
The deep perineal pouch is a human anatomical term that refers to the space enclosed in part by the perineum, and located superior to the perineal membrane.-Structure:...
. However, other sources include the fascia
Fascia
A fascia is a layer of fibrous tissue that permeates the human body. A fascia is a connective tissue that surrounds muscles, groups of muscles, blood vessels, and nerves, binding those structures together in much the same manner as plastic wrap can be used to hold the contents of sandwiches...
as part of the diaphragm. In practice, the two terms are often used interchangeably.
Posteriorly, the pelvic floor extends into the anal triangle
Anal triangle
The anal triangle is the posterior part of the perineum. It contains the anal canal.-Structure:The anal triangle can be defined either by its vertices or its sides.* Vertices** one vertex at the coccyx bone...
.
Function
It is important in providing support for pelvic viscera (organs), e.g. the bladderUrinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
, intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
s, the uterus
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
(in females), and in maintenance of continence as part of the urinary
Urethral sphincter
The term urethral sphincter refers to one of two muscles used to control the exit of urine in the urinary bladder through the urethra. The two muscles are the external urethral sphincter and the internal urethral sphincter...
and anal
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
sphincters. It facilitates birth by resisting the descent of the presenting part, causing the fetus to rotate forwards to navigate through the pelvic girdle.
Clinical significance
In women, the levator muscles or their supplying nerves can be damaged in pregnancy or childbirthChildbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...
. There is some evidence that these muscles may also be damaged during a hysterectomy
Hysterectomy
A hysterectomy is the surgical removal of the uterus, usually performed by a gynecologist. Hysterectomy may be total or partial...
. Pelvic surgery using the "perineal approach" (between the anus and coccyx) is an established cause of damage to the pelvic floor. This surgery includes coccygectomy
Coccygectomy
Coccygectomy is a surgical procedure during which the coccyx, is removed. It can be performed for many reasons for instance in patients with coccyx pain , however it is typically reserved for patients with malignant cancer or for patients whose tailbone pain has failed to respond to nonsurgical...
.
In female high-level athletes, perineal trauma is rare and is associated with certain sports (each with a distinct type of trauma): water-skiing, bicycle racing
Bicycle racing
Bicycle racing is a competition sport in which various types of bicycles are used. There are several categories of bicycle racing including road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX, bike trials, and cycle speedway. Bicycle racing is recognised as an Olympic sport...
, and equestrian sports.
Damage to the pelvic floor not only contributes to urinary incontinence but can lead to pelvic organ prolapse
Prolapse
Prolapse literally means "to fall out of place", from the Latin prolabi meaning "to fall out". In medicine, prolapse is a condition where organs, such as the uterus, fall down or slip out of place. It is used for organs protruding through the vagina or the rectum or for the misalignment of the...
. Pelvic organ prolapse occurs in women when pelvic organs (e.g. the vagina, bladder, rectum, or uterus) protrude into or outside of the vagina. The causes of pelvic organ prolapse are not unlike those that also contribute to urinary incontinence. These include inappropriate (asymmetrical, excessive, insufficient) muscle tone and asymmetries caused by trauma to the pelvis. Age, pregnancy, family history, and hormonal status all contribute to the development of pelvic organ prolapse. The vagina is suspended by attachments to the perineum, pelvic side wall and sacrum via attachments that include collagen, elastin, and smooth muscle. Surgery can be performed to repair pelvic floor muscles. The pelvic floor muscles can be strengthened with Kegel exercises
Kegel exercise
A pelvic floor exercise, more commonly called a Kegel exercise , consists of contracting and relaxing the muscles that form part of the pelvic floor, which are now sometimes colloquially referred to as the "Kegel muscles". Several tools exist to help with these exercises, though many are ineffective...
.
Disorders of the posterior pelvic floor include rectal prolapse
Rectal prolapse
Rectal prolapse normally describes a medical condition wherein the walls of the rectum protrude through the anus and hence become visible outside the body.-Types:There are three chief conditions which come under the title rectal prolapse:...
, rectocele
Rectocele
A rectocele results from a tear in the rectovaginal septum . Rectal tissue bulges through this tear and into the vagina as a hernia...
, perineal hernia
Perineal hernia
Perineal hernia is a hernia involving the perineum . The hernia may contain fluid, fat, any part of the intestine, the rectum, or the bladder. It is known to occur in humans, dogs, and other mammals, and often appears as a sudden swelling to one side of the anus.A common cause of perineal hernia...
, and a number of functional disorders including anismus
Anismus
Anismus is a malfunction of the external anal sphincter and puborectalis muscle during defecation. Normal defecation involves relaxation of both of these muscles...
. Constipation
Constipation
Constipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...
due to any of these disorders is called "functional constipation" and is identifiable by clinical diagnostic criteria.
Pelvic floor exercise (PFE), also known as Kegel exercises, may improve the tone and function of the pelvic floor muscles, which is of particular benefit for women (and less commonly men) who experience stress urinary incontinence. However, compliance with PFE programs often is poor, PFE generally is ineffective for urinary incontinence unless performed with biofeedback
Biofeedback
Biofeedback is the process of becoming aware of various physiological functions using instruments that provide information on the activity of those same systems, with a goal of being able to manipulate them at will...
and trained supervision, and in severe cases it may have no benefit. Pelvic floor muscle tone may be estimated using a perineometer
Perineometer
A perineometer or Kegel perineometer is an instrument for measuring the strength of voluntary contractions of the pelvic floor muscles. Arnold Kegel was the gynecologist who invented the Kegel Perineometer and Kegel exercises...
, which measures the pressure within the vagina. Medication may also be used to improve continence. In severe cases, surgery may be used to repair or even to reconstruct the pelvic floor. It has been reported that patients who have overly-toned musculature may suffer from inability to relax the pelvic floor muscles - in effect, Kegel exercises would only exacerbate the problem. http://www.massagetoday.com/mpacms/mt/article.php?id=13515
Perineology
Perineology
Perineology is a speciality dealing with the functional troubles of the three axis of the female perineum...
or pelviperineology is a speciality dealing with the functional troubles of the three axis (urological, gynaecological and coloproctological) of the pelvic floor.
See also
- CoccyxCoccyxThe coccyx , commonly referred to as the tailbone, is the final segment of the vertebral column. Comprising three to five separate or fused vertebrae below the sacrum, it is attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between...
(Tailbone) - Pubococcygeus musclePubococcygeus muscleThe pubococcygeus muscle or PC muscle is a hammock-like muscle, found in both sexes, that stretches from the pubic bone to the coccyx forming the floor of the pelvic cavity and supporting the pelvic organs. It is part of the levator ani group of muscles.-Function:The Pubococcygeus muscle controls...
- Pelvic floor dysfunction
- PerineologyPerineologyPerineology is a speciality dealing with the functional troubles of the three axis of the female perineum...
- Perineal herniaPerineal herniaPerineal hernia is a hernia involving the perineum . The hernia may contain fluid, fat, any part of the intestine, the rectum, or the bladder. It is known to occur in humans, dogs, and other mammals, and often appears as a sudden swelling to one side of the anus.A common cause of perineal hernia...
External links
- PC Muscles How to Strengthen
- Overview at nih.gov
- Selection of recent medical literature continuously updated on Pelvic Floor Functional Anatomy
- Pelviperineology The Open Access Journal who consider all the compartments of the pelvis and of the perineum, with the body around and the mind above, as a single unit.
- Pelvic Floor Video Video with overview of pelvic floor muscles and related physical therapy exercises
- Pelvic Floor Exercises blog: how to exercise pelvic floor muscles
- Danger of over-toning muscles