3 features of the structure of the female pelvis and 4 rules of female training - Om Activ

• 1 Pelvic bones In men, the bones are thicker, in women they are flatter and hollow - bones of this shape better support female internal organs.
• 2 Muscles In men, in the cavity of the pelvic floor muscles there is a dense muscular-fascial connection that can withstand heavy loads. In women, this area is weakened because the pelvic floor muscle cavity contains an oval opening for the cervix and vagina. According to the results of numerous studies, the pelvic floor muscles in women can withstand loads of up to 10 kg.
• 3 Ligaments Not only muscles, but also ligaments are responsible for ensuring that the internal organs work correctly and are maintained in the correct position inside the abdominal cavity. The structure of muscles is like rubber bands; they can change length - stretch and contract. Ligaments are ropes that bind bones and attach internal organs to the skeleton. Ligaments, like ropes, will not return to their original length after being stretched. They will remain stretched and thin.

Now let's compare the ligaments in men and women.

• 1 Women's ligaments experience greater stress than men's. During intense physical activity, intra-abdominal pressure increases. Women, as you already know, have weaker pelvic floor muscles due to the lack of support from below. Therefore, female ligaments of internal organs are loaded more.
• 2 During pregnancy, women produce the hormone relaxin. This hormone relaxes the ligaments to widen the pelvis for proper pregnancy. Relaxin acts on the entire ligamentous apparatus of a woman, which means that all ligaments temporarily become rubber. Under the influence of relaxin, the ligaments stretch even without unnecessary stress and remain so after the birth of the child.

So how can women exercise to stay healthy?

We cannot influence the shape of the bones, so we will look at how to reduce the load on the ligaments and muscles.

We do not work systematically with large weights

Large ones are heavier than 10 kg. Working with such weights increases intra-abdominal pressure and slowly but surely squeezes the pelvic floor muscles and stretches the ligaments that attach the internal organs. If you lift more at one time, nothing will happen, but regularly lifting heavy weights worsens the condition of the pelvic floor muscles.

During and after pregnancy, a woman should avoid lifting more than 5–7 kilograms.

Each muscle has a maximum load. For example, biceps can withstand x kg. By loading your biceps with 5 kg, you provoke tears and injuries to the ligaments and the muscle itself, as well as neighboring areas that “help” the biceps.

Structure of the woman's pelvis

The anatomy of a woman's pelvis undergoes modifications, starting from the birth of a girl and throughout the stages of growing up. In a born girl, its location is vertical, it is quite narrow, and the entrance has an oval shape. As it grows, the pelvic bones acquire a different shape and size.

Formation depends on a number of reasons:

• genetic characteristics;
• external factors;
• rickets;
• infectious pathologies (for example, polio);
• physical activity;
• spinal and leg injuries.

The female pelvis is an articulation of several types of bones and ligaments between them. The muscle fibers of the spinal column and legs are attached to them.

Big pelvis

It is located in the upper part of the pelvic joint. Along its edges are the iliac bones, behind are the lumbar vertebrae, and in front is the anterior abdominal wall. The value may vary depending on the tension of the abdominal muscles.

In terms of volume, a large pelvis can differ significantly from a small one. Judging by the size of the large one, doctors make a conclusion about the volume of the small one, which is very important for determining the process of childbirth in women. Will it be a natural birth or a caesarean section? Quite often there are cases of impossibility of independent childbirth due to the peculiarities of a woman’s pelvic anatomy.

Small pelvis

This is the bony structure of the birth canal. Consists of an upper plane, a bone cavity and a lower opening.

How is the pelvis formed?

1. Posteriorly represented by the sacrum and coccyx.
2. On the sides by the ischial bones.
3. Anteriorly by the symphysis and pubic bones.
4. Between the two basins there is a border - the nameless line.
5. The female pelvis is represented by two systems.

Obstetrics

Chapter 3 CLINICAL ANATOMY OF THE FEMALE GENITAL ORGANS

STRUCTURE OF THE FEMALE PELVIS

The bony pelvis is of great importance in obstetrics.
It forms the birth canal through which the fetus moves. Unfavorable conditions of intrauterine development, diseases suffered in childhood and during puberty can lead to disruption of the structure and development of the pelvis. The pelvis can be deformed as a result of injuries, tumors, and various exostoses. Differences in the structure of the female and male pelvis begin to appear during puberty and become pronounced in adulthood. The bones of the female pelvis are thinner, smoother and less massive than the bones of the male pelvis. The plane of entrance to the pelvis in women has a transverse oval shape, while in men it has the shape of a card heart (due to the strong protrusion of the promontory).

Anatomically, the female pelvis is lower, wider and larger in volume. The pubic symphysis in the female pelvis is shorter than the male one. The sacrum in women is wider, the sacral cavity is moderately concave. The pelvic cavity in women is closer to a cylinder in outline, and in men it narrows funnel-shaped downwards. The pubic angle is wider (90 – 100°) than in men (70 – 75°). The tailbone protrudes anteriorly less than in the male pelvis. The ischial bones in the female pelvis are parallel to each other, and in the male pelvis they converge.

All of these features are very important in the process of birth.

The pelvis of an adult woman consists of 4 bones: two pelvic, one sacral and one coccygeal, firmly connected to each other.

Hip bone,

or
innominate
(os coxae, os innominatum), up to 16–18 years of age, consists of 3 bones connected by cartilage in the area of ​​the acetabulum (acetabulum): iliac (os ileum), ischial (os ischii) and pubis (os pubis). After puberty, the cartilages fuse together and a solid bone mass is formed - the pelvic bone.

On the ilium

distinguish between the upper section - the wing and the lower section - the body. At the site of their connection, an inflection is formed, called an arcuate or nameless line (linea arcuata, innominata). There are a number of protrusions on the ilium that are important to the obstetrician. The upper thickened edge of the wing - the iliac crest (crista iliaca) - has an arched curved shape and serves to attach the broad abdominal muscles. In front it ends with the anterior superior iliac spine (spina iliaca anterior superior), and at the rear with the posterior superior iliac spine (spina iliaca posterior superior). These two spines are important for determining the size of the pelvis.

Ischium

forms the lower and posterior thirds of the pelvic bone. It consists of a body involved in the formation of the acetabulum and a branch of the ischium. The body of the ischium with its branch forms an angle, open anteriorly; in the area of ​​the angle, the bone forms a thickening - the ischial tubercle (tuber ischiadicum). The branch is directed anteriorly and upward and connects with the lower branch of the pubic bone. On the back surface of the branch there is a protrusion - the ischial spine (spina ischiadica). There are two notches on the ischium: the greater sciatic notch (incisura ischiadica major), located below the posterior superior iliac spine, and the lesser sciatic notch (incisura ischiadica minor).

Pubic

, or
pubic bone,
forms the anterior wall of the pelvis, consists of a body and two branches - the upper (ramus superior ossis pubis) and the lower (ramus inferior ossis pubis). The body of the pubis forms part of the acetabulum. At the junction of the ilium and the pubis there is the iliopubic eminence (eminentia iliopubica).

The upper and lower branches of the pubic bones in front are connected to each other through cartilage, forming a sedentary joint, a semi-joint (symphysis ossis pubis). The slit-like cavity in this junction is filled with fluid and increases during pregnancy. The lower branches of the pubic bones form an angle - the pubic arch. Along the posterior edge of the superior branch of the pubic bone stretches the pubic crest (crista pubica), which passes posteriorly into the linea arcuata of the ilium.

Sacrum

(os sacrum) consists of 5 – 6 vertebrae motionlessly connected to each other, the size of which decreases downwards. The sacrum has the shape of a truncated cone. The base of the sacrum faces upward, the apex of the sacrum (narrow part) faces downward. The anterior surface of the sacrum has a concave shape; it shows the junction of the fused sacral vertebrae in the form of transverse rough lines. The posterior surface of the sacrum is convex. The spinous processes of the sacral vertebrae, fused together, run along the midline. The first sacral vertebra, connected to the V lumbar vertebra, has a protrusion - the sacral promontory (promontorium).

The coccyx (os coccygis) consists of 4–5 fused vertebrae. It connects to the sacrum via the sacrococcygeal joint. There are cartilaginous layers at the joints of the pelvic bones.

FEMALE PELVIS FROM AN OBSTETRIC POINT OF VIEW

There are two sections of the pelvis: the large and small pelvis. The boundary between them is the plane of the entrance to the small pelvis.

Big pelvis

limited laterally by the wings of the ilium, posteriorly by the last lumbar vertebra.
In front it has no bony walls. is of greatest importance in obstetrics .
The birth of the fetus occurs through the small pelvis. There are no simple ways to measure the pelvis. At the same time, the dimensions of the large pelvis are easy to determine, and on their basis one can judge the shape and size of the small pelvis.

Small pelvis

is the bony part of the birth canal. The shape and size of the small pelvis are very important during childbirth and determining the tactics of its management. With sharp degrees of narrowing of the pelvis and its deformations, childbirth through the natural birth canal becomes impossible, and the woman is delivered by cesarean section.

The posterior wall of the pelvis is made up of the sacrum and coccyx, the lateral ones are the ischial bones, and the anterior wall is made up of the pubic bones with the pubic symphysis. The upper part of the pelvis is a continuous ring of bone. In the middle and lower thirds the walls of the small pelvis are not solid. In the lateral sections there are large and small sciatic foramina (foramen ischiadicum majus et minus), limited respectively by the large and small sciatic notches (incisura ischiadica major et minor) and ligaments (lig. sacrotuberale, lig. sacrospinale). The branches of the pubic and ischial bones, merging, surround the obturator foramen (foramen obturatorium), which has the shape of a triangle with rounded corners.

In the small pelvis there are an entrance, a cavity and an exit. In the pelvic cavity there are wide and narrow parts. In accordance with this, four classic planes are distinguished in the small pelvis (Fig. 1).

The plane of entrance to the small pelvis is limited in front by the upper edge of the symphysis and the upper inner edge of the pubic bones, on the sides by the arcuate lines of the ilium and behind by the sacral promontory. This plane has the shape of a transverse oval (or kidney-shaped). It distinguishes three sizes (Fig. 2): straight, transverse and 2 oblique (right and left). The direct dimension is the distance from the superior inner edge of the symphysis to the sacral promontory. This size is called the true, or obstetric, conjugate (conjugata vera) and is equal to 11 cm. In the plane of the entrance to the pelvis, an anatomical conjugate (conjugata anatomica) is also distinguished - the distance between the upper edge of the symphysis and the sacral promontory. The size of the anatomical conjugate is 11.5 cm. The transverse dimension is the distance between the most distant sections of the arcuate lines. It is 13.0 - 13.5 cm. The oblique dimensions of the plane of entrance to the small pelvis are the distance between the sacroiliac joint of one side and the iliopubic eminence of the opposite side. The right oblique size is determined from the right sacroiliac joint, the left - from the left. These sizes range from 12.0 to 12.5 cm.

The plane of the wide part of the pelvic cavity

in front it is limited by the middle of the inner surface of the symphysis, on the sides - by the middle of the plates covering the acetabulum, in the back - by the junction of the II and III sacral vertebrae. In the wide part of the pelvic cavity there are 2 sizes: straight and transverse. Direct size - the distance between the junction of the II and III sacral vertebrae. In the wide part of the pelvic cavity there are 2 sizes: straight and transverse. Direct size - the distance between the junction of the II and III sacral vertebrae and the middle of the inner surface of the symphysis. It is equal to 12.5 cm. The transverse dimension is the distance between the middles of the internal surfaces of the plates covering the acetabulum. It is equal to 12.5 cm. Since the pelvis in the wide part of the cavity does not represent a continuous bone ring, oblique dimensions in this section are allowed only conditionally (13 cm each).

Rice. 1. Classic planes and straight dimensions of the small pelvis:

1

– anatomical conjugate:
2
– true conjugate;
3
– direct size of the wide part of the pelvic cavity;
4
– direct size of the narrow part of the pelvic cavity;
5 – direct size of the plane of exit from the pelvis during pregnancy; 6
– direct size of the plane of exit from the small pelvis during childbirth;
7 –
wire pelvic axis

The plane of the narrow part of the pelvic cavity

bounded in front by the lower edge of the symphysis, on the sides by the spines of the ischial bones, and behind by the sacrococcygeal joint. In this plane there are also 2 sizes. Straight size - the distance between the lower edge of the symphysis and the sacrococcygeal joint. It is equal to 11.5 cm. The transverse dimension is the distance between the spines of the ischial bones. It is 10.5 cm.

Rice. 2. Plane of entry into the pelvis:

1

– straight size;
2
– transverse size;
3
– left oblique size;
4
– right oblique size

Rice. 3. Plane of exit from the pelvis:

1

– straight size;
2
– transverse dimension

Exit plane

from the small pelvis (Fig. 3) is limited in front by the lower edge of the pubic symphysis, on the sides by the ischial tuberosities, and behind by the apex of the coccyx. Straight size - the distance between the lower edge of the symphysis and the tip of the coccyx. It is equal to 9.5 cm. When the fetus passes through the birth canal (through the plane of exit from the pelvis), due to the posterior movement of the coccyx, this size increases by 1.5 - 2.0 cm and becomes equal to 11.0 - 11.5 cm Transverse size - the distance between the inner surfaces of the ischial tuberosities. It is equal to 11.0 cm.

When comparing the sizes of the small pelvis in different planes, it turns out that in the plane of the entrance to the small pelvis the transverse dimensions are maximum, in the wide part of the pelvic cavity the direct and transverse dimensions are equal, and in the narrow part of the cavity and in the plane of the exit from the small pelvis the direct dimensions are greater than the transverse ones .

In obstetrics, in some cases, the system of parallel Goji planes

(Fig. 4). The first, or upper, plane (terminal) passes through the upper edge of the symphysis and the border (terminal) line. The second parallel plane is called the main plane and passes through the lower edge of the symphysis parallel to the first. The fetal head, having passed through this plane, does not subsequently encounter significant obstacles, since it has passed through a solid bone ring. The third parallel plane is the spinal one. It runs parallel to the previous two through the spines of the ischial bones. The fourth plane, the exit plane, runs parallel to the previous three through the apex of the coccyx.

Rice. 4. Parallel planes of the pelvis:

1

– terminal plane;
2
– main plane;
3
– spinal plane;
4
– exit plane

All classic planes of the pelvis converge anteriorly (symphysis) and fan out posteriorly. If you connect the midpoints of all straight dimensions of the small pelvis, you will get a line curved in the shape of a fishhook, which is called the wire axis of the pelvis

. It bends in the pelvic cavity according to the concavity of the inner surface of the sacrum. The movement of the fetus along the birth canal occurs in the direction of the pelvic axis.

Pelvic angle

- this is the angle formed by the plane of the entrance to the pelvis and the horizon line. The angle of inclination of the pelvis changes as the center of gravity of the body moves. In non-pregnant women, the pelvic inclination angle is on average 45 - 46°, and the lumbar lordosis is 4.6 cm (according to Sh. Ya. Mikeladze).

As pregnancy progresses, lumbar lordosis increases due to a shift in the center of gravity from the area of ​​the II sacral vertebra anteriorly, which leads to an increase in the angle of inclination of the pelvis. As lumbar lordosis decreases, the pelvic inclination angle decreases. Up to 16 – 20 weeks. During pregnancy, no changes are observed in the position of the body, and the angle of inclination of the pelvis does not change. By the gestational age of 32 - 34 weeks. lumbar lordosis reaches (according to I.I. Yakovlev) 6 cm, and the pelvic inclination angle increases by 3 - 4°, amounting to 48 - 50° (Fig. 5).

Rice. 5. Pelvic inclination angle:

A

– in a woman’s standing position;
b
– in a woman’s lying position

The angle of inclination of the pelvis can be determined using special instruments designed by Sh. Ya. Mikeladze, A. E. Mandelstam, as well as manually. With the woman lying on her back on a hard couch, the doctor places her hand (palm) under the lumbosacral lordosis. If the hand moves freely, then the angle of inclination is large. If the hand does not pass, the pelvic inclination angle is small. You can judge the angle of inclination of the pelvis by the ratio of the external genitalia and hips. With a large angle of inclination of the pelvis, the external genitalia and genital cleft are hidden between the closed thighs. With a low angle of inclination of the pelvis, the external genitalia are not covered by closed thighs.

You can determine the angle of inclination of the pelvis by the position of both iliac spines relative to the pubic joint. The angle of inclination of the pelvis will be normal (45 - 50°) if, with the woman’s body in a horizontal position, the plane drawn through the symphysis and the upper anterior iliac spines is parallel to the horizontal plane. If the symphysis is located below the plane drawn through the indicated spines, the angle of inclination of the pelvis is less than normal.

The small angle of inclination of the pelvis does not prevent the fixation of the fetal head in the plane of the entrance to the small pelvis and the advancement of the fetus. Childbirth proceeds quickly, without damage to the soft tissues of the vagina and perineum. A large pelvic inclination angle often presents an obstacle to fixation of the head. Incorrect insertion of the head may occur. During childbirth, injuries to the soft birth canal are often observed. By changing the position of the mother's body during childbirth, it is possible to change the angle of inclination of the pelvis, creating the most favorable conditions for the advancement of the fetus along the birth canal, which is especially important if the woman has a narrowing of the pelvis.

The angle of inclination of the pelvis can be reduced by lifting the upper part of the body of a lying woman, or by placing the woman in labor on her back, by bringing her legs bent at the knees and hip joints to her stomach, or by placing a pad under the sacrum. If the pole is located under the lower back, the angle of the pelvis increases.

PARIETAL MUSCLES OF THE PELVIC AND MUSCLES OF THE PELVIC FLOOR

The soft tissues of the small pelvis, lining the birth canal, do not reduce its size. The pelvic muscles create the best conditions for the advancement of the fetal head during childbirth.

The plane of entrance to the small pelvis on both sides is partially covered by m. iliopsoas. The lateral walls of the pelvis are lined with obturator (m. obturatorius) and piriformis (m. piriformis) muscles. They contain blood vessels and nerves. The sacral cavity is covered by the rectum. Behind the pubic joint is the bladder, surrounded by loose tissue.

The area of ​​exit from the pelvic cavity is called the perineum

(perineum). The crotch area is diamond-shaped; in front it extends to the lower edge of the pubic symphysis, in the back - to the apex of the coccyx, on the sides it is limited by the branches of the pubic and ischial bones and the ischial tuberosities.

The perineal area (regio perinealis) forms the floor of the pelvis, closing the exit from it. It is divided into the anterosuperior, lesser, genitourinary region

(regio urogenitalis) and the infero-posterior, large,
anal region
(regio analis). The boundary of these two areas is a slightly convex posterior line connecting the right and left ischial tuberosities.

Two diaphragms take part in the formation of the pelvic floor - the pelvic

(diaphragma pelvis) and
genitourinary
(diaphragma urogenitalis). The pelvic diaphragm occupies the back of the perineum and has the shape of a triangle, the apex of which faces the coccyx and the corners face the ischial tuberosities.

Pelvic diaphragm.

The superficial layer of the muscles of the pelvic diaphragm is represented by the unpaired muscle -
the external anal sphincter
(m. sphincter ani externus). This muscle covers the perineal section of the rectum. It consists of several bundles, the superficial of which end in the subcutaneous tissue. The bundles, starting from the top of the coccyx, cover the anus and end in the tendon center of the perineum. The deepest bundles of this muscle are adjacent to the levator ani muscle.

The deep muscles of the pelvic diaphragm include two muscles: the levator ani muscle and the coccygeus muscle.

Levator ani muscle

(m. levator ani), - steam room, triangular in shape, forms a funnel with a similar muscle on the other side, the wide part facing upward. The lower parts of both muscles, tapering, cover the rectum in the form of a loop.

This muscle consists of the pubococcygeus (m. pubococcygeus) and iliococcygeus muscles (m. iliococcygeus).

Pubococcygeus muscle

(m. pubococcygeus) with its lateral part starts from the anterior section of the tendinous arch of the levator ani muscle (arcus tendineus m. levatoris ani). The internal sections of this muscle begin near the superomedial part of the obturator foramen from the inner surface of the rami of the pubis. The muscle is directed back down and medially to the coccyx and is attached to the anal-coccygeal ligament (lig. anococcygeum), to the sacrococcygeal ligament (lig. sacrococcygeum), weaving part of the bundles into the muscular lining of the vagina, partly into the longitudinal layer of the muscular lining of the rectum. In front, the pubococcygeus muscle is adjacent to the urethra.

Iliococcygeus muscle

(m. iliococcygeus) also begins from the tendinous arch, posterior to the beginning of the pubococcygeus muscle. The muscle runs back down and medially and attaches to the coccygeal bone below the pubococcygeus muscle.

Coccygeus muscle

(m. coccygeus) in the form of a triangular plate is located on the inner surface of the sacrospinous ligament. With a narrow apex it starts from the ischial spine, and with a wide base it is attached to the lateral edges of the lower sacral and coccygeal vertebrae.

Urogenital diaphragm

- This is a fascial-muscular plate (Fig. 6), located in the anterior part of the pelvic floor between the lower branches of the pubic and ischial bones. This plate includes the upper and lower fascia of the genitourinary diaphragm. Both fascia fuses on each side with the periosteum of the lower rami of the pubis and with the periosteum of the ischial bones. Between the upper and lower fascia of the urogenital diaphragm there is a deep perineal space (spatium perinei profundum).

The muscles of the urogenital diaphragm are divided into superficial and deep.

The superficial ones include the superficial transverse perineal muscle, the ischiocavernosus muscle and the bulbospongiosus muscle.

Superficial transverse perineal muscle

(m. transversus perinei superficialis) – steamy, unstable, sometimes may be absent on one or both sides. This muscle is a thin muscular plate located at the posterior edge of the urogenital diaphragm and running across the perineum. With its lateral end it is attached to the ischium, with its medial part it crosses along the midline with the muscle of the same name on the opposite side, partially intertwining with the bulbospongiosus muscle, and partially with the external muscle that compresses the anus.

Ischiocavernosus muscle

(m. ischiocavernosus) – a steam room that looks like a narrow muscle strip. It begins as a narrow tendon from the inner surface of the ischial tuberosity, bypasses the stalk of the clitoris and is woven into its tunica albuginea.

Bulbospongiosus muscle

(m. bulbospongiosus) – steam room, surrounds the entrance to the vagina, has the shape of an elongated oval. This muscle starts from the tendinous center of the perineum and the external sphincter of the anus and is attached to the dorsal surface of the clitoris, intertwined with its tunica albuginea.

The deep muscles of the urogenital diaphragm include the deep transverse perineal muscle and the urethral sphincter.

Rice. 6. Urogenital diaphragm:

1

– m.
ischiocavernosus; 2
– bulbus vestibuli;
3
– m.
transversus perinei profundus; 4
– glandula vestibularis major;
5
– anus et m.
sphincter ani externus; 6
– m.
bulbospongiosus; 7
– m.
transversus perinei superficialis; 8
– fascia diaphragmatis urogenitalis inferior;
9
– ostium vaginae;
10
– ostium uretrae externum;
11
– clitoris

Deep transverse perineal muscle

(m. transversus perinei profundus) is a paired, narrow muscle starting from the ischial tuberosities (posterior to the attachment of m. ischiocavernosus). It goes to the midline, where it connects with the muscle of the same name on the opposite side, participating in the formation of the tendon center of the perineum.

Sphincter of the urethra

(m. sphincter urethrae) – steam room, lies in front of the previous one. Peripherally located bundles of this muscle are directed to the branches of the pubic bones and to the fascia of the genitourinary diaphragm. Bundles of this muscle surround the urethra. This muscle connects to the vagina.

The structure of the pelvic floor muscles is necessary to know to study the biomechanism of childbirth.

All the muscles of the pelvic floor form, as they expand, one elongated tube, consisting of individual muscular tubes, which only touch their edges. As a result, the tube, instead of an almost straight direction from the symphysis to the apex of the coccyx, takes an oblique direction, bending backwards and in the form of an arc.

Male pelvis

Usually it is approximately 1.7 cm smaller than a woman's. The difference in size may depend on several reasons, for example, age, type of posture of a person.

Its cavity includes the following organs:

• intestinal loops;
• appendix.

The pelvic inlet in men is narrower than in women, and the tailbone is slightly less forward. Lymphatic and large blood vessels are also located here.

Differences between male and female

The anatomical features of the female pelvis differ from the male pelvis in a number of ways.

The difference between the female and male pelvis begins to appear as boys and girls grow up.

The anatomy of the pelvic joint is quite complex. Violations of its integrity entail negative consequences. Such as dysfunction, lameness.