Dynamics of the human spine

The skeleton of the spine serves as a solid support of the trunk and consists of 33-34 vertebrae. The vertebra includes two parts - the vertebral body (in front) and the vertebra arch (posterior). The vertebral body has the bulk of the vertebra. The vertebra arc consists of four segments. Two of these are the legs forming the supporting walls. The other two parts are thin plates, which form a kind of "roof". Three bone processes depart from the vertebrae. From each "leg-plate" connection, the right and left transverse processes branch off. In addition, on the midline, when the person is tilted forward, one can see a protruding spinous process. Depending on the location and function of the vertebrae of different departments have specific features in the structure, and the direction and degree of movement of the vertebra are determined by the orientation of the articular processes.

Cervical vertebrae. The articular processes have a flat oval shape and are located in space at an angle to the frontal plane of 10-15 °, to the sagittal plane - 45 °, to the horizontal plane - 45 °. Thus, any displacement produced by the above-mentioned joint with respect to the lower one will occur at an angle simultaneously to the three planes. The vertebral body has a concavity of the upper and lower surfaces and is considered by many authors as a factor contributing to an increase in the volume of motion.

Thoracic vertebrae. The articular processes are inclined to the frontal plane at an angle of 20 °, to the sagittal - at an angle of 60 °, horizontal and frontal - at an angle of 20 °.

This spatial arrangement of the joints facilitates the movement of the superior joint relative to the lower one at a time ventrocranially or dorsocadally in conjunction with its medial or lateral bias. The predominant inclination of the articular sites is in the sagittal plane.

Lumbar vertebrae. The spatial interposition of their articular areas differs from the thoracic and cervical divisions. They have an arcuate shape and are located to the frontal plane at an angle of 45 °, to the horizontal plane - at an angle of 45 °, to the sagittal plane at an angle of 45 °. This spatial arrangement facilitates the movement of the superior joint relative to the lower one, both dorsolaterally and ventromedially in combination with cranial or caudal displacement.

The important role of intervertebral joints in the movement of the spine is also evidenced by the well-known works of Lesgaft (1951), in which great attention is paid to the coincidence of the centers of gravity of the spherical surface of the joints in the C5-C7 segments. This explains the prevailing volume of movement in them. In addition, the inclination of articular surfaces simultaneously to the frontal, horizontal and vertical planes promotes simultaneous linear motion in each of these three planes, excluding the possibility of one-plane motion. In addition, the shape of the joint articulations facilitates the sliding of one joint in the plane of the other, limiting the possibility of simultaneous execution of angular motion. These representations are consistent with the studies of White (1978), which, after removal of articular processes with arches, increased the volume of angular motion in the vertebral motor segment in the sagittal plane by 20-80 %, frontal - by 7-50%, horizontal - by 22-60 %. The data of the X-ray study of Jirout (1973) confirm these results.

In the spinal column there are all kinds of joints of bones: continuous (syndesmosis, synchondrosis, synostosis) and discontinuous (joints between the vertebral column and skull). The vertebral bodies are interconnected by intervertebral disks, which together constitute approximately the entire length of the spinal column. They mainly serve as hydraulic shock absorbers.

It is known that the magnitude of mobility in any part of the spine depends to a large extent on the ratio of the height of intervertebral discs and the bone part of the spinal column.

According to Kapandji (1987), this ratio causes mobility of a certain segment of the spinal column: the higher the ratio, the greater the mobility. The cervical spine has the greatest mobility, since this ratio is 2: 5, or 40%. The lumbar region is less mobile (ratio 1: 3, or 33%). The thoracic area is even less mobile (ratio 1: 5, or 20%).

Each disk is constructed in such a way that inside it has a gelatinous nucleus and a fibrous ring.

The gelatinous core consists of an incompressible gel-like material enclosed in an elastic "container". Its chemical composition is represented by proteins and polysaccharides. The core is characterized by a powerful hydrophilicity, i.e. Attraction to water.

According to Puschel (1930), at birth, the liquid content in the core is 88%. With age, the nucleus loses its ability to bind water. By the age of 70, the water content in it has been reduced to 66%. The causes and consequences of this dehydration are of great importance. Reduction of the water content in the disk can be explained by a decrease in the concentration of protein, polysaccharide, and by gradual replacement of the gel-like core material with fibrous cartilaginous tissue. The results of studies by Adams and co-authors (1976) showed that with age, the molecular size of proteoglycans changes in the gelatinous nucleus and in the fibrous ring. The liquid content decreases. By the age of 20, the vascular supply of the disks disappears. By the age of 30, the disk is fed solely by diffusion of lymph through the end plates of the vertebrae. This explains the loss of flexibility of the spine with age, as well as a disruption in the ability of the elderly to restore the elasticity of the injured disc.

The gelatinous nucleus takes forces acting vertically on the body of the vertebrae and distributes them radially in the horizontal plane. In order to better understand this mechanism, it is possible to represent the nucleus in the form of a movable hinged joint.

Fibrous ring consists of approximately 20 concentric layers of fibers, they are interwoven in such a way that one layer is at an angle to the previous one. Such a structure provides traffic control. For example, under the action of a shearing force, oblique fibers that go in one direction tend to strain, while those going in the opposite direction relax.

Functions of the gelatinous nucleus (Alter, 2001)

Act	Bending	Extension	Lateral flexion
Upper vertebra is raised	Front	Rear	To the flexion side
Consequently, the disc straightens	Front	Rear	To the flexion side
Consequently, the disk increases	Rear	Front	To the side opposite to the bend
Consequently, the core is sent	Forward	Go back	To the side opposite to the bend

Fibrous ring with age loses its elasticity and compliance. At a young age, the fiber-elastic fabric of the ring is predominantly elastic. With age or after injury, the percentage of fibrous elements increases and the disc loses its elasticity. As the loss of elasticity, it becomes more susceptible to injury and damage.

Each intervertebral disc can be shortened in height by an average of 1 mm under the influence of a load of 250 kg, which for the spinal column as a whole gives a shortening of about 24 mm. At a load of 150 kg, the shortening of the intervertebral disc between T6 and T7 is 0.45 mm, and a load of 200 kg causes the disc to be shortened between T11 and T12 by 1.15 mm.

These disc changes from pressure disappear rather quickly. When lying for half an hour, the length of the body of a person growing from 170 to 180 cm, increases by 0.44 cm. The difference in the length of the body of the same person in the morning and evening is determined by an average of 2 cm. According to Leatt, Reilly, Troup (1986), a 38.4% decrease in growth was observed in the first 1.5 hours after waking and 60.8% in the first 2.5 hours after awakening. The recovery of growth by 68% occurred in the first half of the night.

Analyzing the difference in height in children in the morning and afternoon hours, Strickland and Shearin (1972) revealed an average difference of 1.54 cm, and the amplitude of the oscillations was 0.8-2.8 cm.

During sleep, the load on the vertebral column is minimal and the discs swell, absorbing the liquid from the tissues. Adams, Dolan and Hatton (1987) identified three significant effects of daily fluctuations in the amount of load on the lumbar spine: 1 - "swelling" causes increased stiffness of the spinal column during flexion in the lumbar spine after waking; 2 - early in the morning for ligaments of vertebral column discs, a higher risk of damage is characteristic; 3 - the amplitude of movements of the spinal column increases by the middle of the day. The difference in the length of the body depends not only on the decrease in the thickness of the intervertebral discs, but also on the change in the height of the arch of the foot and possibly also to some extent on the change in the thickness of the cartilage of the joints of the lower limbs.

Disks can change their shape under the influence of force before the sexual maturity of a person. By this time, the thickness and shape of the discs are finally determined, and the configuration of the spine and the posture associated with it become permanent. However, it is precisely because posture depends mainly on the features of the intervertebral discs that it is not a completely stable sign and can change to some extent under the influence of external and internal force effects, in particular physical exercises, especially at a young age.

An important role in determining the dynamic properties of the spinal column is played by ligamentous structures and other connective tissues. Their task is to limit or modify the motion of the joint.

The front and back surfaces of the vertebral bodies and intervertebral discs pass the anterior and posterior longitudinal ligaments.

Between the arcs of the vertebrae are very strong ligaments consisting of elastin fibers, which give them a yellow color, so that the ligaments themselves are called intercostal, or yellow. When the spinal column moves, especially when flexing, these ligaments stretch and tense.

Between the spinous processes of the vertebrae there are interstitial ones, and between the transverse processes there are interdigital ligaments. Above the spinous processes along the entire length of the spinal column passes the supraspinous ligament, which, approaching the skull, increases in the sagittal direction and is called the ligamentous ligament. In humans, this ligament looks like a wide plate, forming a kind of septum between the right and left muscle groups of the nuchal region. Articular processes of the vertebrae are connected with each other by joints, which are flat in the upper parts of the spinal column, and cylindrical in the lower part, in particular in the lumbar region.

The connection between the occipital bone and the atlas has its own peculiarities. Here, as well as between the articular processes of the vertebrae, there is a joint joint consisting of two anatomically detached joints. The shape of the articular surfaces of the atlantocapital articulation is ellipsoidal or ovoid.

Three joints between the atlant and the epistrophe are combined into a combined Atlanto-axial joint with one vertical axis of rotation; of them unpaired is the joint of cylindrical shape between the tooth of the epistrophe and the front arch of the atlas and the paired joint - a flat joint between the lower articular surface of the atlas and the upper articular surface of the epistrophe.

Two joints, atlanto-occipital and atlantoove, located above and below the atlas, complement each other, form joints giving the head mobility around three mutually perpendicular axes of rotation. Both of these joints can be combined into one combined joint. When the head rotates around the vertical axis, the atlas moves along with the occipital bone, playing the role of an intervening meniscus between the skull and the rest of the spinal column. In the strengthening of these joints, a rather complicated ligamentous apparatus is involved, which includes the cruciform and pterygoid ligaments. In turn, the cruciate ligament consists of a transverse ligament and two legs - the upper and lower. The transverse ligament passes behind the tooth of the epistrophe and strengthens the position of this tooth in its place, being stretched between the right and left lateral masses of the atlas. The upper and lower legs move away from the transverse ligament. Of these, the upper is attached to the occipital bone, and the lower one to the body of the second cervical vertebra. Pterygoid ligaments, right and left, go from the lateral surfaces of the tooth upwards and outwards, attaching to the occipital bone. Between the atlas and the occipital bone there are two membranes (membranes) - anterior and posterior, covering the opening between these bones.

The connection of the sacrum with the coccyx occurs via synchondrosis, in which the coccyx can shift mainly in the anteroposterior direction. The amplitude of the mobility of the tip of the coccyx in this direction in women is approximately 2 cm. In the strengthening of this synchondrosis, the ligamentous apparatus also participates.

Due to the fact that the vertebral column in an adult forms two lordotic (cervical and lumbar) and two kyphotic (thoracic and sacral-coccygeal) bends, a vertical line starting from the center of gravity of the body crosses it only in two places, most often at the level of C8 and L5 vertebrae. These relationships, however, may vary depending on the characteristics of the human posture.

The severity of the upper half of the body not only exerts pressure on the vertebrae, but also affects some of them in the form of a force forming the spinal column bends. In the thoracic region, the line of gravity of the body passes in front of the vertebral bodies, in connection with which there is a force action aimed at increasing the kyphotic bending of the spinal column. This is hampered by its ligamentous apparatus, in particular, the posterior longitudinal ligament, the interoast ligaments, and the tone of the extensor musculature of the trunk.

In the lumbar spine the ratios are inverse, the line of gravity of the body usually passes so that gravity tends to reduce the lumbar lordosis. With age, both the resistance of the ligamentous apparatus and the tone of the extensor muscles decrease, and due to this, under the influence of gravity, the vertebral column most often changes its configuration and forms one common bend directed forward.

It has been established that the shift of the center of gravity of the upper half of the body forward occurs under the influence of a number of factors: mass of the head and shoulder girdle, upper limbs, thorax, thoracic and abdominal organs.

The frontal plane, in which the center of gravity of the body is located, differs relatively little from the atlanto-occipital joint in adults. In young children, the mass of the head is of great importance, because its relation to the mass of the whole body is more significant, so the frontal plane of the center of gravity of the head is usually more displaced anteriorly. The mass of the upper limbs of a person affects to a certain extent the formation of the spinal column bends, depending on the shift of the shoulder girdle forward or backward, as the specialists noticed a certain correlation between the stoop and the degree of displacement of the shoulder girdle and upper limbs forward. However, with straightened posture, the shoulder belt is usually displaced backward. The mass of the human chest increases the more the center of gravity of the trunk is moved forward, the stronger its anteroposterior diameter is developed. With a flat chest, its center of mass lies relatively close to the spinal column. Breasts and especially the heart not only contribute to their mass displacement of the center of mass of the trunk forward, but also act as a direct traction on the cranial part of the thoracic spine, thereby enhancing its kyphotic bend. The weight of the abdominal organs varies depending on the age and constitution of the individual.

Morphological features of the spinal column determine its strength for compression and stretching. In the literature, there are indications that he can withstand the compression pressure of about 350 kg. Resistance to compression for the cervical region is approximately 50 kg, for the breast - 75 kg and for the lumbar - 125 kg. It is known that the tensile strength is about 113 kg for the cervical, 210 kg for the thoracic and 410 kg for the lumbar spine. The connection between the V lumbar vertebra and the sacrum is broken at a draft of 262 kg.

Strength of individual vertebrae for compression of the cervical region is approximately the following: C3- 150 kg, C4- 150 kg, C5- 190 kg, C6- 170 kg, C7-170 kg.

For the thoracic region, the following indicators are typical: T1 - 200 kg, T5 - 200 kg, T3 - 190 kg, T4 - 210 kg, T5 - 210 kg, T6 - 220 kg, T7- 250 kg, T8 - 250 kg, T9 - 320 kg, T10 - 360 kg, T11 - 400 kg, T12 - 375 kg. The lumbar department can withstand approximately the following loads: L1 - 400 kg, L2 - 425 kg, L3 - 350 kg, L4 - 400 kg, L5 - 425 kg.

Between the bodies of two adjacent vertebrae the following types of movements are possible. Movement along the vertical axis as a result of compression and stretching of intervertebral discs. These movements are very limited, since compression is possible only within the elasticity of the intervertebral discs, and tension is inhibited by longitudinal ligaments. For the spinal column in general, the limits of compression and extension are negligible.

The movements between the bodies of two adjacent vertebrae can partially occur in the form of rotation around the vertical axis. This movement is inhibited mainly by the stress of concentric fibers of the fibrous ring of the intervertebral disc.

Between the vertebrae, rotations are also possible around the frontal axis during flexion and extension. With these movements, the shape of the intervertebral disc changes. When flexing, its front part is squeezed and the posterior part is stretched; when the extension is observed the opposite phenomenon is observed. In this case, the jelly nucleus changes its position. When folded, it moves backward, and when extended, it moves forward, that is, toward the elongated part of the fibrous ring.

Another pronounced kind of movement is the rotation around the sagittal axis, which leads to a lateral torso of the trunk. At the same time, one side of the disk is squeezed, and the other is stretched, and the gelatinous nucleus moves toward the extension, i.e., toward the convexity.

The movements occurring in the joints between two adjacent vertebrae depend on the shape of the articular surfaces, which are located differently in different parts of the vertebral column.

The most mobile is the cervical section. In this department the articular processes have flat articular surfaces directed backwards approximately at an angle of 45-65 °. This type of articulation gives three degrees of freedom, namely: the flexion-extensor movements in the frontal plane, lateral movements in the sagittal plane and rotational movements in the horizontal plane are possible.

In the interval between C2 and C3 vertebrae, the amplitude of the movements is somewhat less than that between the other vertebrae. This is because the intervertebral disc between these two vertebrae is very thin and because the anterior part of the lower edge of the epistrophe forms a protrusion that limits movement. The amplitude of flexion-extensor movement in the cervical region is approximately 90 °. The convexity forward, formed by the anterior contour of the cervical region, changes during concavity into concavity. The resulting concavity has a radius of 16.5 cm. If we draw radii from the anterior and posterior ends of this concavity, we obtain an angle that is open back and equal to 44 °. With the maximum extension, an angle is created, which is open forwards and upwards and is equal to 124 °. The chords of these two arcs are connected at an angle of 99 °. The greatest amplitude of motion is noted between C3, C4 and C5 vertebrae, somewhat smaller - between C6 and C7 and even smaller - between C7 and T1 vertebrae.

Lateral movements between the bodies of the first six cervical vertebrae also have a rather large amplitude. The vertebra C ... Is much less mobile in this direction.

Saddle articular surfaces between the bodies of the cervical vertebrae do not favor torsion movements. In general, according to different authors, the amplitude of movements in the cervical region is on the average such values: flexion - 90 °, extension - 90 °; lateral slope - 30 °, rotation in one direction - 45 °.

The Atlas occipital articulation and the joint between the atlant and the epistrophe in the complex have three degrees of freedom of movement. In the first of these, head inclinations are possible forwards and backwards. In the second, it is possible to rotate the atlas around the tooth-shaped process, and the skull rotates together with the atlant. The inclination of the head forward in the joint between the skull and the atlas is only possible by 20 °, the inclination backward by 30 °. The backward movement is inhibited by the tension of the anterior and posterior atlantocapital membranes and occurs around the frontal axis passing behind the external auditory aperture and immediately in front of the mastoid processes of the temporal bone. A greater than 20 ° inclination of the skull forward and 30 ° back is possible only with the cervical spine. A forward slope is possible before the chin touches the sternum. Such a degree of slope is achieved only with an active contraction of the muscles, bending the cervical spine and tilting the head on the trunk. When the head descends forward by gravity, the chin usually does not touch the sternum, because the head is held by the tension of the stretched muscles of the posterior surface of the neck and the ligamentous ligament. The severity of the leaning forward head when it acts on a first-order lever is insufficient to overcome the passivity of the back muscles of the neck and the elasticity of the ligamentous ligament. With the contraction of the sternum and the chin and sublingual muscles, their strength, together with the severity of the head, causes a greater stretching of the muscles of the posterior surface of the neck and the ligamentous ligament, as a result of which the head tilts forward until the chin contacts the sternum.

In the joint between the atlas and the epistle, a turn of 30 ° to the right and to the left is possible. Rotation in the joint between the atlant and the epistle is limited by the tension of the pterygoid ligaments originating on the lateral surfaces of the condyles of the occipital bone and attached to the lateral surfaces of the tooth-shaped process.

Due to the fact that the lower surface of the cervical vertebrae is concave in the anteroposterior direction, movements between the vertebrae in the sagittal plane are possible. In the cervical spine, the ligament apparatus is the least powerful, which also contributes to its mobility. The cervical region is much less (in comparison with the thoracic and lumbar divisions) subject to the action of compressive loads. It is the place of attachment for a large number of muscles, which determine the movements of the head, spine and shoulder girdle. At the neck, the dynamic effect of muscle traction is relatively greater in comparison with the action of static loads. The cervical area is not very susceptible to deforming loads, because the surrounding muscles, as it were, protect it from excessive static effects. One of the characteristic features of the cervical region is that the flat surfaces of the articular processes with the vertical position of the body are at an angle of 45 °. When the head and neck are tilted forward, this angle increases to 90 °. In this position, the articular surfaces of the cervical vertebrae are superimposed on each other in the horizontal direction and are fixed due to the action of the musculature. With a bent position of the neck, the action of the muscles is especially significant. However, the bent posture of the neck is habitual for a person at work, since the organ of vision must control the movements of the hands. Many types of work, as well as reading books are usually carried out with an inclined position of the head and neck. Therefore, the muscles, in particular, the posterior surface of the neck, have to be included in the work to keep the head in balance.

In the thoracic region articular processes also have flat articular surfaces, but they are oriented almost vertically and are located mainly in the frontal plane. With this arrangement of the processes, flexion and rotation are possible, and the extension is limited. Lateral slopes are carried out only in insignificant limits.

In the thoracic spine mobility is the smallest, which is due to the small thickness of intervertebral discs.

Mobility in the upper part of the thoracic region (from the first to the seventh vertebra) is insignificant. It increases in the caudal direction. Lateral slopes in the thoracic region are possible approximately 100 ° to the right and somewhat less to the left. Rotational movements are limited by the position of the articular processes. The amplitude of the movements is quite significant: around the front axis is 90 °, extension is 45 °, rotation is 80 °.

In the lumbar region, the articular processes have articulating surfaces oriented almost in the sagittal plane, their upper-joint articular surface concave, and the lower-convex convex. This arrangement of the articular processes excludes the possibility of their mutual rotation, and movements are made only in the sagittal and in the frontal planes. In this case, the extensor motion is possible in a larger range than the bending motion.

In the lumbar region, the degree of mobility between the different vertebrae is not the same. In all directions, it is greatest between vertebrae L3 and L4, and also between L4 and L5. The least mobility is noted between L2 and L3.

The mobility of the lumbar spine is characterized by the following indices: flexion - 23 °, extension - 90 °, lateral slope to each side - 35 °, rotation - 50. The greatest mobility is characterized by the intervertebral space between L3 and L4, which should be compared with the fact of the central position of the vertebra L3 . Indeed, this vertebra corresponds to the center of the abdominal region in men (in women, L3 is somewhat more caudal). There are cases when the sacrum in man was located almost horizontally, and the lumbosacral angle decreased to 100-105 °. Factors limiting movement in the lumbar spine are presented in Table. 3.4.

In the frontal plane, flexion of the spine is possible mainly in the cervical and upper thoracic areas; Extension is mainly carried out in the cervical and lumbar regions, in the thoracic region these movements are insignificant. In the sagittal plane, the greatest mobility is noted in the cervical region; in the thoracic region it is insignificant and increases again in the lumbar part of the spine. Rotation is possible in large areas in the cervical region; in the caudal direction, its amplitude decreases and is very small in the lumbar region.

When studying the mobility of the spine as a whole has no arithmetical meaning, to summarize the figures characterizing the amplitude of movements in different departments, since movements of the entire free part of the spine (both on anatomical preparations and on living subjects) cause compensatory movements due to bending of the spinal column. In particular, dorsal flexion in one department can cause ventral extension in the other. Therefore, it is expedient to supplement the study of the mobility of various departments with data on the mobility of the spinal column as a whole. In the study of an isolated vertebral column, the following data were obtained by a number of authors in this respect: flexion 225 °, extension 203 °, inclination 165 °, rotation 125 °.

In the thoracic region, lateral flexion of the spinal column is possible only when the articular processes are located exactly in the frontal plane. However, they are tilted somewhat forward. As a result, only those intervertebral joints participate in the lateral incline, the facets of which are oriented approximately in the frontal plane.

Rotational movements of the spine around the vertical axis are possible to the greatest extent in the neck. The head and neck can be rotated with respect to the body by approximately 60-70 ° in both directions (ie, approximately 140 ° apart). In the thoracic spine, rotation is impossible. In the lumbar region, it is practically zero. The greatest rotation is possible between the thoracic and lumbar divisions in the 17th and 18th biokinematic pairs.

The total rotational mobility of the vertebral column as a whole is thus 212 ° (132 ° for the head and neck and 80 ° for the 17th and 18th biokinematic pairs).

It is of interest to determine the possible degree of rotation of the body around its vertical axis. When standing on one leg, rotation in a half-bent hip joint is possible by 140 °; when supported by both legs, the amplitude of this movement decreases to 30 °. In total, this increases the rotational capacity of our body to about 250 ° when standing on two legs and up to 365 ° - while standing on one leg. Rotational movements, produced from head to foot, cause a decrease in body length by 1-2 cm. However, in some people this decrease is significantly greater.

Torsion movement of the spinal column is carried out at four levels, characteristic of various types of scoliotic bends. Each of these levels of twisting depends on the function of a specific muscle group. The lower level of rotation corresponds to the lower aperture (level XII of the false ribs) of the thorax. Rotational movement at this level is due to the function of the internal oblique muscle of one side and the external oblique muscle of the opposite side acting as synergists. This movement can be continued upward due to a reduction in internal intercostal muscles on one side and external intercostals on the other. The second level of rotational movements is at the shoulder girdle. If it is fixed, the rotation of the chest and spinal column is caused by contraction of the anterior dentate and pectoral muscles. Rotation is also provided by some back muscles - posterior jagged (upper and lower), ilio-rib and semi-ovoid. The thoracic-clavicular-mastoid muscle with bilateral contraction keeps the head in an upright position, throws it back, and also bends the cervical spine. With one-sided cutting, he tilts his head in his direction and turns into the opposite one. The belt muscle of the head unbends the cervical spine and turns its head in the same direction. The belt of the neck extends the cervical spine and turns the neck toward the contraction.

The slopes toward the chato are combined with its rotation, because this is favored by the location of the intervertebral joints. The movement takes place around an axis that is not exactly in the sagittal direction, but is inclined forward and downward, so that the slope to the side is accompanied by the rotation of the trunk back on the side where the convexity of the spinal column is formed when tilted. The combination of slopes to the sides with rotation is a very significant feature that explains some of the properties of scoliotic bends. In the region of the 17th and 18th biokinematic pairs, the slopes to the sides of the spinal column are combined with its rotation into a convex or concave side. In this case, it is common for him to implement such a triad of movements: tilt to the side, bend forward and rotate toward the convexity. These three movements are usually realized with scoliotic bends.

[1], [2], [3], [4], [5],

Functional groups of muscles that provide movement of the spinal column

Neck section: movements around the front axis

Bending

1. Breast-clavicular-mastoid muscle
2. Anterior staircase
3. Back stair
4. Long Neck Muscle
5. The long muscle of the head
6. Anterior rectus muscle of the head
7. Subcutaneous Neck Muscle
8. Spade-and-hyoid muscle
9. Breast-hyoid muscle
10. Chest and thyroid
11. Subctal duodenum
12. Digastric
13. Szilovidyazychnaya muscle
14. Jaw-hyoid muscle
15. Chin-hyoid muscle

Movement around the sagittal axis

1. Long Neck Muscle
2. Anterior staircase
3. Medium staircase
4. Back stair
5. Trapezius muscle
6. Breast-clavicular-mastoid muscle
7. Muscle, straightening the spine
8. Neck strap muscle
9. The long muscle of the head

Movement around the vertical axis - twisting

1. Anterior staircase
2. Medium staircase
3. Back stair
4. Breast-clavicular-mastoid muscle
5. The upper part of the trapezius muscle
6. Neck strap muscle
7. Muscle lifting shoulder blade

Circular movements in the cervical region (circumduction):

With the alternate participation of all muscle groups that produce flexion, tilt rhone and extension of the spine in the cervical region.

Lumbar section: movements around the front axis

Bending

1. Ilio-lumbar muscle
2. Square lumbar muscle
3. Straight abdominal muscle
4. Outer oblique abdominal muscle

Extension (thoracic and lumbar parts)

1. Muscle, straightening the spine
2. Transverse muscle
3. Interstitial muscles
4. Transversal muscles
5. Muscles lifting the ribs
6. Trapezius muscle
7. The widest back muscle
8. Large diamond-shaped muscle
9. Small rhomboid muscle
10. Upper posterior cog muscle
11. Lower posterior cog muscle

Movement in the sides (lateral flexion) around the sagittal axis (thoracic and lumbar spine)

1. Transversal muscles
2. Muscles lifting the ribs
3. Outer oblique abdominal muscle
4. Inner oblique abdominal muscle
5. Transverse abdominal muscle
6. Straight abdominal muscle
7. Square lumbar muscle
8. Trapezius muscle
9. The widest back muscle
10. Large diamond-shaped muscle
11. Upper posterior cog muscle
12. Lower posterior cog muscle
13. Muscle, straightening the spine
14. Transverse-awned muscle

Movement around the vertical axis - twisting

1. The ileal lumbar muscle
2. Muscles lifting the ribs
3. Square lumbar muscle
4. Outer oblique abdominal muscle
5. Inner oblique abdominal muscle
6. External intercostal muscle
7. Internal intercostal muscle
8. Trapezius muscle
9. Large diamond-shaped muscle
10. The widest back muscle
11. Upper posterior cog muscle
12. Lower posterior cog muscle
13. Muscle, straightening the spine
14. Transverse muscle

Circular rotational movements with mixed axes (circumduction): with alternate contraction of all the muscles of the trunk that produce extension, hollow to the side and flexion of the spinal column.