Tasks on the theme of autumn in kindergarten. Lexical theme: Autumn. Game "Autumn riddles"
All human actions are expressed in movements.
Movement is a complex of psychophysiological functions implemented by the dynamic apparatus of a person.
Thanks to movements, a person affects the world and changes it, but the movements themselves also change.
Rubinstein emphasizes: human movements are the ability to perform an action aimed at solving a specific problem. The nature or content of the task determines the movement.
Since the time of Sechenov, arbitrary and involuntary have been distinguished.
The main properties of the movement:
- Speed;
- Power;
- Pace
- Rhythm
- Accuracy and Accuracy
- Plasticity and dexterity
Types of movement
Rubinstein highlights 6 types of movements:
- Movement of the posture (muscular apparatus) - static reflexes that provide maintenance and change in the posture of the body;
- Location movement(associated with movement) - features are distinguished in gait and posture;
- Expressive movements of the face and the whole body(facial expressions and pantomimics);
- Semantic movements(e.g. hat removal, handshake);
- Speech as a motor function(dynamics, rhythm, intonation, stress);
- labor movement- movements that exist in various types labor operations.
developed the problem of the mechanisms of organization of human movements and actions. Before him there was classical physiology. Bernstein created non-classical physiology.
The difference between classical and non-classical physiology:
- Classical physiology relies on the mechanism of the S-R model;
- Classical physiology is the physiology of animals, where the principle of reactivity contributed. She had little contact with practice. Non-classical physiology turned to the study of man. object studies were the natural movements of a normal intact organism.
- Bernstein's physiology was based on the principle of integrity. He argued with Pavlov that a reflex is not an element of action, but an elementary action, an integral act that begins and continues to completion.
- Bernstein contrasted the principle of reactivity with the principle of activity. That is, all processes of reception (acceptance of energy) and centers that process information are a manifestation of activity.
Book published in 1947 "On building a movement".
In 1966, the year of death Alexander Nikolaevich Bernstein, his last book was published "Essays on the physiology of movements and the physiology of activity" where the concept is presented.
The concept of "model of the required future"
Alexander Nikolaevich Bernstein introduced the concept of a "model of the necessary future", considering it as one of the forms of displaying the world by a living organism. The second form is the reflection of the past and present. Along with this, the brain “reflects” (constructs) the situation of the future, which has not yet become a reality, which its biological needs encourage to realize. Only a clear image of the required future can serve as a basis for formulating a problem and programming its solution.
Unlike the model of the future, the model of the future has a probabilistic character.
The principle of sensory corrections
Bernstein proposed a completely new principle of motion control, calling it the principle of sensory corrections. This refers to corrections made to motor impulses based on sensory information about the course of movement. The result of any complex movement depends not only on the actual control signals, but also on a number of additional factors. The common property of these factors is to make changes in the planned course of movements. Movement, even the most elementary, is always built "here and now", and does not follow automatically - every time the same thing - after the stimulus that caused it.
The ultimate goal of a movement can only be achieved if it is constantly amended (corrections). The central nervous system must know what the real fate of the current movement is, that is, it must continuously receive afferent signals containing information about the actual course of movement, and then process them into correction signals.
Factors affecting the course of movement:
- Reactive forces- involuntary reactions that occur in the systems of muscles, tendons, bones, and so on. If you wave your hand strongly, then reactive forces will develop in other parts of the body, which will change their position and tone. For example, if a child climbs onto a sofa and starts throwing the ball from it, then by throwing the ball, he himself can fly off the sofa.
- Inertial forces- if you raise your hand sharply, then it will take off only due to those motor impulses that are sent to the muscle, but from some moment they will move by inertia (that is, longer than necessary).
- Outside forces(external resistance) are obstacles that can get in the way of a running program. If the movement is directed towards an object, then it necessarily meets with its resistance, which is not always predictable.
- Initial state of the muscle- (this is the position of the arm, the degree of muscle contraction, etc.) the state changes in the course of movement along with a change in its length, as well as as a result of its fatigue, etc. Therefore, the same control impulse, having come to the muscle, can give a completely different motor effect.
The action of all these factors necessitates continuous accounting of information about the state of the motor apparatus and the direct course of movement. This information is called "feedback signals" . Feedback signals from movements are often paralleled, that is, they arrive simultaneously through several channels. For example, when a person walks, he feels his steps with the help of a muscular sense and can simultaneously see and hear them.
Levels of construction of movements
Bernstein is the creator of the theory of movement levels. He found that, depending on what information the feedback signals carry, afferent signals arrive at different sensory centers of the brain and, accordingly, switch to motor pathways at different levels.
The level should be understood as morphological "layers" in the CNS. Thus, the levels of the spinal and medulla oblongata, the level of subcortical centers, and the levels of the cortex were identified.
Each level has specific motor manifestations peculiar only to it, it implements its own class of movements.
Level A- the lowest and phylogenetically the most ancient ( rubrospinal). To this level signals from muscle proprioceptors(receptors located in the muscles of the body), reporting on the degree of muscle tension, as well as from the balance organs.
Level A participates in the organization of any movement together with other levels and almost never leads a person. There are movements that are regulated by level A independently: involuntary trembling, chattering of teeth from cold and fear, trembling of a violinist's finger, and so on.
Level B- Bernstein called level of synergies(from Greek acting together; synergists are muscles that act together to carry out one specific movement). By the name of the anatomical substrate, it is called talamo-pallidar. At this level signals are processed from muscle-articular receptors that report on the relative position and movements of body parts.
Level B participates in the organization of movements of higher levels, taking on the task internal coordination, highly coordinated movements of the whole body. It is responsible for the automation of various motor skills, expressive facial expressions and pantomime movements, expressively colored. The own movements of this level include those that do not require consideration of external space: freestyle gymnastics, sipping, facial expressions, etc.
Level C- Bernstein calls the level of the spatial field. By the name of the anatomical substrate - pyramidal striatal. They apply to him signals from sight, hearing, touch, that is, all information about the external space. These are all moving movements: walking, climbing, running, jumping, various acrobatic movements, ball throws, playing tennis, aiming movements (playing billiards, aiming a telescope).
Level D - level of substantive actions. This cortical level. By the name of the anatomical substrate - parieto-premotor. He is in charge of organization of actions with objects and is specific to a person. It includes all gun actions, all everyday movements, work, driving. The movements of this level are consistent with the logic of the object. This is not so much a movement as an action. They do not fix the motor composition, but set the final result. For this level, the method of performing an action, a set of motor operations is indifferent.. For example, a bottle can be opened with a corkscrew, the cork can be knocked out by hitting the bottom, the cork can be pushed in, etc. In all cases, the result is the same.
Level E - the level of intellectual-motor acts, first of all speech movements, writing movements, movements of symbolic speech (gestures of the deaf and dumb) . The anatomical substratum of movements at this level is not very clear, but Bernstein emphasized the involvement frontal cortex brain, referring to the work of Luria.
Should be considered:
- Several levels are involved in the organization of complex actions at once. The one on which the action is built is called the leader, and the rest are the underlying ones.
- Formally, the same action can be built at different levels. For example, a circular motion of the hands can be obtained at level A, or at level B, or at level C, or at level D.
What determines the fact of building a movement at one level or another?
The leading level of building a movement is determined by the meaning or task of the movement. That is, physiology is determined by completely non-physiological things, namely, the purpose of human action.
Thus, Bernstein introduced the target determination of the behavior of an organism.
Bernstein's contribution
Bernstein's ideas are of great importance for psychology. He made major contributions to several branches of psychology:
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Part 14 -
Part 15 -
Part 16 - Actions and movements. Levels of construction of movements (according to N. A. Bernshtein)
Part 17 -
Part 18 -
Movement levels. Sensory corrections and two cycles of interactions as a principle of motor system self-regulation in health and disease. The theory of skill education. Classification of movement disorders in cerebral palsy on the basis of a defective level of coordination.
Movement is a quality inherent in all living things, whether it is the flow of fluid in plants, blood cells in the vascular bed, the movement of animals and humans in space, or the socially determined actions of an individual.
The formation of movement, the improvement of its qualities, such as speed, accuracy, smoothness, etc., is a process that obeys the universal laws of the construction of movements. It is based on the improvement of coordination (joint - from Latin ordinatio - ordering, interconnection, alignment. In biology - the correlative development of organs and parts of the body in their historical development).
The laws of construction of movements were first defined by our compatriot N.A. Bernshtein in the forties and fifties. The encyclopedia reports: “Bernshtein Nikolai Alexandrovich (1896-1966) - neuro- and psychophysiologist, creator of the physiology of activity. His research in the physiology of movement theoretical basis modern biomechanics, some of his ideas anticipated a number of provisions of cybernetics”. Based on the laws he derived, the science of artificial control systems, manipulators, and robots developed. His scientific fate, unfortunately, resembles the fate of progressive biologists and geneticists of that time.
Bernstein's principles were then deciphered and concretized by many researchers (Anokhin P.K., Gurfinkel V.S., 1960, etc.).
Human movements have a beginning in their development, a period when the qualities of movement (speed, accuracy, etc.) reach perfection, and involution - fading, loss of these qualities.
This principle is most noticeable in the formation of locomotion, in particular, walking (locomotion - from the Latin lokus - place and motio - movement. In biology, this is a cyclically repeating regular sum of automatic movements that ensure active movement in space - walking, swimming, bird flight etc.).
We all watched how clumsy, inaccurate movements of a child of 1 - 1.5 years old become sweet and graceful in their own way by 3 - 5 years.
At the age of puberty, hormonal disturbances again make movements angular, sharp, awkward. By old age, the control mechanisms wear out, and movements become fussy, uncertain. Old man stomps for a long time before getting off the footboard of the bus, stepping over a puddle, as if trying on space. It is more and more difficult to maintain stability when walking, and the old person deliberately reduces the portable period of the step, since relying on one leg at this moment carries the risk of losing stability - the gait becomes shuffling.
The enormous influence of emotions on the pattern of movements is known: the walking of the prisoner and the winner is not comparable, although it consists of the same structural elements. Movements of a ballerina, mime is a silent expression of the whole gamut of feelings from tragedy to triumph, deaf-mute movements of hands and face replace speech. With movements, you can depict a dying swan and even melted ice cream and drying cheese.
Such perfection of movements is not inherited. The infant does not have the qualitative characteristics of the movements of the father and mother. He again goes through the whole path of development of movements - from the most primitive to highly coordinated and socially significant actions. What is this path, how is it connected with the development of brain structures and peripheral mechanisms, how does the development of a skill, the improvement of the qualities of movement - these questions are answered by the theory of construction of movements proposed by Bernstein. It includes several key points:
the first provision is about the unity of onto- and phylogenesis of movements; the second provision is about the stepwise development of movements, about the levels of construction of movements in the central nervous system;
the third provision is about the reflex ring and sensory corrections;
the fourth provision is about two cycles of interaction; the fifth provision is about the development of skill.
Let's take a closer look at each of these postulates.
Movement is a property common to the entire animal kingdom. Ultimately, this is a fight for life. It depends on the qualities of movement - “you will be eaten or you will be eaten”, which is the essence of the law of natural selection: the strongest survives, possessing high speed, agility, endurance, quick reaction, the ability to hit the target, protected by a shell, etc. Therefore, this is how The structures of the brain that control movement are complex, repeatedly duplicated at all stages of development, which is why the process of improving coordination mechanisms is so lengthy and thorough, and therefore, with local lesions of the brain by trauma or illness, movement, although it acquires a pathological character, does not disappear completely. Nature loses none of her earlier acquisitions in this process.
The formation of human movements, including locomotion, repeats phylogenesis in ontogenesis (ontogeny - from Greek ontos - existing and genesis - origin. In biology, ontogenesis is the process of individual development, phylogeny (from Greek phylon - clan, tribe) the historical development of the world organisms - species, classes, etc.).
In phylogenesis, the process of control, coordination of actions originates in unicellular organisms, where a signal of danger or the proximity of prey is transmitted by contact, which is chemotaxis (from the Greek chemo - chemistry and tachis - device). In biology, chemotaxis is the movement of the simplest organisms under the influence of changes in the concentration of chemical stimuli. The response to irritation is possible only in the immediate vicinity of the stimulus. The next stage of evolution is multicellular organisms. The mechanism for coordinating the functions of a multicellular system becomes more complicated. At this stage of development of regulation, each cell releases the products of its vital activity into the intercellular space, reporting information about itself to the entire system. This is a humoral way of managing, structurally and functionally more differentiated. A noticeable stage in evolution was the appearance of oblong forms of living objects. The appearance of this feature was the progress of evolution, since the oblong shape reduces the front of danger for the animal. But it also gives rise to a lot of problems in management, since the parts of the body that are posterior to the main - head - end must be protected and obedient, must be ready to perform a more complex motor task, i.e., more highly coordinated in their actions . To perform the motor tasks of this plan, evolution generates a remote way of perceiving an object - a receptor apparatus appears (from Latin receptor - receiving, receptio - acceptance). In biology, receptors are the endings of sensitive nerve fibers or specialized cells - the retina of the eye, the inner ear, etc., which convert irritation perceived from the outside (exteroceptors) or from the internal environment of the body (interoceptors) into nervous excitation transmitted to the central nervous system. Telereceptors (from the Greek She - far away) - receptors that receive signals at a distance - this is the mechanism of vision, hearing, etc. The appearance of telereceptors is considered as a leap, a revolution in the development of movements, since this is already the ability to see in advance prey or danger, to prepare for the performance of the corresponding motor task - to ensure one's safety or take possession of the victim. The task becomes more complicated, and at the same time the control and executive apparatus become more complex - the center of control centers appears - the brain, the musculoskeletal system is improved. N.A. Bernshtein writes that the appearance of the striated muscle in the phylogenesis was a mystery of evolution. This acquisition of nature had both positive and negative (in terms of management) consequences. Positive was the increase in power capabilities, facilitating the solution of complex motor tasks, the speed of responses, posture stability, endurance during prolonged work.
It became possible not only to move the body, but also to move with the help of the limbs - walking, flying, swimming, etc. Negative, if I may say so, was the need to complicate the control systems and the executive apparatus of movements - the muscular and skeletal systems. The structure of the muscle changes dramatically. The muscle is therefore called striated, which consists of alternating, great friends from each other, structural elements visible microscopically as red and white transverse stripes.
Structure is driven by function. The muscle in terms of control works on the principle of “all or nothing”. Under these conditions, it is difficult to dose the effort adequate to the motor task to be solved (in fact, coordination), and nature endows the muscle with a fibrous structure, the ability to include not all fibers in the work, but what is necessary in this moment their number, and “shock absorbers”, which are connective tissue layers (white stripes between red ones), which ensure smooth movement. For the function of such a muscle, a rigid system of support and movement is needed - the skeleton. The skeleton performs not only a motor, but also a protective function (tortoise shell, skull, protecting the delicate tissue of the brain from damage). The skeleton must be rigid, but at the same time very mobile, obedient, those. there is a need for movable and inactive joints that have an appropriate form for the function and a number of degrees of freedom determined for each joint.
The degree of freedom in biomechanics is the ability to move in a certain direction. For a block-shaped joint, two degrees of freedom are possible (for example, for a knee joint, this is flexion and extension).
At the same time, control mechanisms are also being improved. The central nervous system becomes more and more complex, more highly differentiated brain structures appear. The process of development of brain control structures is not unsystematic, not chaotic, but obeys completely definite laws. In the vast, multi-million world of brain cells, a hierarchy is built in a certain sequence and within strictly defined time limits of its formation - the subordination of lower brain structures to higher ones. Hierarchy (from the Greek hieros - sacred, ogsiyo - power) - the arrangement of parts or elements of the whole in order from higher to lower. In the theory of organization of functions, this is the principle of control.
We turn to the deciphering of the second position of Bernstein's theory, namely, to the concept of levels of construction of movements in onto- and phylogenesis. Earlier, the improvement of the mechanisms of the managerial and executive apparatus was briefly described. From a comparison of the biomechanical and neurophysiological characteristics of movements, in particular locomotion, Bernstein concludes that the differentiated movements of higher animals and humans are the product of improving the control mechanisms of lower organization.
Table I
Phylo- and ontogeny of regulation of movements (according to N.A. Bernshtein)
ny systems by creating structures, which he called the levels of construction of movements.
To decipher this position, he introduces the term function localization. Localization (from Latin lokus, lokalis - place, local), according to Bernstein, is a complex of brain structures responsible for performing a certain class of movements. The class of movements is the movements that are characteristic of an animal at a certain stage of its motor development. (Further on, this last concept will be characterized more broadly.) He emphasizes that the term of function localization is not a topic - the topographic anatomy of the brain (from the Greek topos - place, grapho - I write), and the function and morphological content embedded in this concept are similar on the function and arrangement of the blocks of radio receiver panels, when the individual parts of the whole are not necessarily always nearby, in the same place, as topographic anatomy dictates. Moreover, the maturation of brain structures included in the concept of localization can be extended in time, when some elements are already ready to perform a function, while others are in the process of formation. This, apparently, can explain the great difficulty in educating certain movements, when a delay in the development of one of the elements of localization makes it impossible at the moment to educate some movement - be it playing the piano, skating or self-service skills. That is why it is advisable to start training in sports or learning the art of dancing and playing musical instruments at a certain age. This can explain the complexity, a huge spread, but also a certain pattern of pathology of posture and walking in cerebral palsy.
The difference between the concept of topic and localization is illustrated by an example when, with damage to certain brain structures, the patient cannot complete the “raise your hand” task, but when asked to take off his hat, he will quite easily and freely raise the same hand.
Based on the foregoing, Bernstein proposes a scheme for constructing movements or levels of coordination in phylo- and ontogenesis.
Each level of coordination includes an afferent system, a center, and an efferent system. (Afferent - from lat. afferens - bringing, efferent - from lat. efferens - outgoing.) In biology, respectively, - transferring a nerve impulse to the center or from the center to the working organ.
We have compiled Bernstein's information about the scheme of building movement or coordination in a table (Table I).
In the scheme, for each level of coordination, the morphological substrate of the central nervous system, the age of its final formation, the afferent system, the class of movements organized by this level of coordination, and the specific elements of a person’s posture and locomotion introduced into the control of this particular level are indicated.
Levels of coordination of the prelocomotor period: rubrospinal, thalamo-pallidar. striatal-pyramidal, consisting of two sublevels - striatal and pyramidal.
This is followed by the levels of regulation of movements when locomotion is already formed: the parieto-premotor (the level of objective actions and semantic goals) and a group of higher cortical levels that provide writing, speech, etc., the coverage of which is beyond the scope of this book.
Rubrospinal level - the most ancient - paleokinetic (from the Greek. palaios - ancient, kinesis - movement) - the level of coordination of movements.
Its name includes the Latin definition of the red nucleus of the brain (nucleus - nucleus, rubrum - red) and nuclei of the spinal cord (from Latin spina - ridge, in anatomy - spinal - spinal).
Its morphological substrate is the afferents of the vestibular apparatus, receptors of the skin, tendons, muscles and articular capsules, receptors of cross-reflexes of paired limbs and interlimb (from Latin reflekxus - turned back, reflected, in biology - the body's response to irritation of receptors), reflexes of internal organs: vasomotor, urinary, defecation.
It completes its development in utero. The class of movements provided by this level of coordination consists of movements of a swimming nature - slow or swift, continuous or suddenly turning into immobility, movements in which almost 100% of the musculature of the body is involved. Their character resembles the movements of fish.
The talamo-pallidar level is another mechanism for regulating movements, ready to function even before birth. Its name is due to Latin terms: thalamus - visual tubercle, in anatomy - the main part of the diencephalon, the main subcortical center, directing impulses of all types of sensitivity - temperature, pain, etc. - to the brain stem, subcortical nodes and the cerebral cortex. Pallidum (from Latin globus pallidum - pale ball) in humans regulates vegetative functions. This level provides the major tremendous synergy of walking with the rhythmic sequence of engaging almost 100% of the skeletal muscles. (Synergy - from the Greek sinergBs - acting together. In biology, synergists are muscles that act together to carry out one specific movement, for example, inhalation, in which intercostal, intercartilaginous and diaphragmatic muscles participate simultaneously.)
The thalamo-pallidar level, together with the rubrospinal level, provide a balance mechanism - antigravitational - and a certain character of fetal movements in the amniotic fluid of the uterine cavity.
It should be noted here that in works on anthropology (from the Greek. anthropos - a person, logos - a word, teaching) there is information that the age dynamics of the trabecular structure of the vertebrae speaks of the fetal spine as a functioning organ.
Curious from these positions is the discovery of American scientists, who proved that the fetus 8 - 12 weeks already hears. This interesting fact would be set as follows: the father of the child, pressing his head to the mother's stomach, hummed the same melody. After birth, the baby always clearly reacted to this melody, calmed down and stopped crying.
Clinicians are well aware that the buckling movements of the fetus occur at very specific times of its development so clearly that the time of movement is one of the criteria for determining the gestational age.
It can be assumed that in a child with a complicated birth, who will be diagnosed with cerebral palsy, the most ancient mechanism for coordinating movements is already defective. In this case, many features of the course of pregnancy and childbirth will become clear, such as late fetal movement, its incorrect position (transverse, etc.) in the uterine cavity, incorrect insertion of the head when passing through the birth canal, entanglement with the umbilical cord, one end of which motionlessly attached to the wall of the uterine cavity (for example, a small puppy tied to a booth, wrapped in a chain, may die), fast or, on the contrary, slow births, premature or late births. All of these signs are often noted in the anamnesis of children with cerebral palsy. This idea is also suggested by the fact that movement disorders in cerebral palsy, with all their diversity, are classified into certain groups in which the pattern of movements is of the same type. Yes, and it is difficult to assume that obstetricians in Russia, the USA, India, etc. are equally careless in obstetric care.
From these positions birth trauma- peripheral paralysis of the hands, fractures of the clavicles, hematomas and other complications could be considered not as a cause, but as a consequence - a consequence of a disturbed program of fetal movements. Based on this, it would probably be necessary to study, using ultrasound or other methods of research, the patterns of fetal movements, their pattern, and if signs of risk are found, offer C-section instead of stimulating the labor activity of the uterus, which in this situation will only increase fetal hypoxia.
The afferent system of this level of regulation is the receptors of the vestibular apparatus, which are designed to signal the position of body parts in space (otolith apparatus) and the speed and direction of movements (semicircular canals of the inner ear). The labyrinth system, the red nucleus, the optic tubercle, as well as the nuclei of the cerebellum are normally formed by the time of birth and can fully function.
There is reason to assume that complications during pregnancy and childbirth may come from the defectiveness of the structural elements of the rubrospinal and thalamo-pallidar levels of movement construction, expressed in varying degrees of severity and causing further pathogenesis of posture and walking deformities in a child with cerebral palsy after his birth. The baby is born "thalamo-pallidar" and the movements of the newborn are dictated by this matured level of coordination. The class of movements regulated by the rubrospinal level of coordination is superimposed by movements of the class of the thalamo-pallidar level. At the same time, nature does not lose its early mechanisms of coordination, and each next, more highly differentiated level changes the characteristics of movement in the direction of their complication, improvement in accordance with a more complex motor task, while using the expedient elements of a more primitive class of movements.
So, smooth, alternating with immobility, continuous movements of the rubrospinal level (similar to athetoid hyperkinesis) move into the area of vegetative functions, such as intestinal motility, contractions of the vascular wall, and the work of sphincters. Bladder and anus. The stepping synergy of the thalamo-pallidar level of coordination, which includes almost the entire skeletal muscles, serves as the foundation for the organization of bipedal walking, instead of the many-legged and trunk locomotion of lower animals (Table I). In the evolution of higher animals and humans, nature also uses such primitive methods of control that are characteristic of unicellular organisms. An example is the movement of blood cells in the vascular bed. Studies have shown that this is not a process of passive movement of cells in the blood plasma flow, but active, regulated movements of blood cells.
As follows from the scheme, global flexion synergy belongs to the class of movements of the thalamo-pallidar level. Clinically, it looks like this: if you ask the patient to bend one leg at the knee, automatic flexion always occurs simultaneously in the hip, knee and ankle joints of both legs (Fig. 1 A, B). Isolated movement is not possible. When kneeling, the patient falls forward or cannot assume a vertical kneeling position at all, folding like a penknife, but can nevertheless maintain an upright torso position in a sitting position with bent legs.
With a severe degree of defectiveness of this level, a person cannot sit down on his own, planted, does not hold a sitting position.
Tracing the evolution of the child's movements, one can observe that up to a certain age a healthy child cannot perform this task either, but then, along with the maturation of the structures and the striatal level following it in the hierarchical ladder, motor synergies seem to be localized, limited in the volume of functioning muscles and joints, and thus more differentiated and expedient postures and movements become possible. Such differentiation is possible with the maturation, as mentioned above, of the striatal level of coordination, when stepping synergy begins to correlate with the features of space - obstacles, uneven ground, steps, etc. Striatum - from lat. korpus striatum - striatum. In anatomy - highly diffe-
A. Patient with global flexion synergy. An attempt to flex in the right knee joint is accompanied by synergistic flexion in the hip and knee joints, dorsiflexion in the hip and knee joints, dorsiflexion of the feet and an increase in the depth of the lumbar lordosis. Isolated movement is not possible. B. EMG of the flexor muscles of the left leg. An attempt to flex in the right (contralateral) knee joint is accompanied by high electrical activity of the flexor muscles of the left leg.
a regressed formation of the brain, which plays the role of a regulator and brake of the gross reflex activity of the pallidum. It is known that a child who is just starting to walk still “does not know heights”, does not step over obstacles, etc.
Global, large-scale motor synergies are being replaced by more localized ones. This process normally ends by 2 years of age. A sign of the localization of this kind of motor synergy is the so-called Strümpel's tibial synkinesis, which he described in the 1920s. He regarded it as a neurological symptom that serves as a differential sign of damage to the pyramidal tract. The pyramidal level of movement regulation, according to Bernstein, is next to the striatal level, i.e., Shtrumpel's data indirectly confirm the legitimacy of classifying the levels of movement construction.
Strumpel's tibial synkinesis is clinically interpreted as automatic dorsiflexion and supination of the foot with simultaneous plantar flexion of the first toe of this foot. An analysis of the electromyographic and biomechanical structure of walking allows us to state that the indicated synkinesis (from the Greek sun - together, kinema, kinematos - movement) is an element of a healthy person's locomotion and serves to transfer the foot over the support. It becomes clearly visible only in extreme situations: at a high pace of walking, when overcoming sudden obstacles.
With inadequate control of the pyramidal level of coordination, tibial synkinesis, not being limited in the amplitude of the previously indicated movements and the time of their manifestation within the expedient, becomes pathological and causes such features of the posture and walking in cerebral palsy as instability of the ankle. joint in the sagittal plane, a significant weakening of the rear push when walking, the posture of the so-called triple flexion when standing.
The pyramidal level completes the prelocomotor period of development of coordinations. This level sets it in motion meaning(go there, bring something, etc.). A sign of the formation of this level in locomotion is the ability to produce an isolated movement.
With insufficient pyramidal level of coordination, as indicated above, it is difficult or even impossible, for example, dorsiflexion of the foot. When asked to do only this movement, its isolated flexion occurs in a minimal amount, and when the command “bend the knee” the foot automatically bends sometimes until the back of the foot touches the surface of the lower leg. A similar situation is also observed in an electromyographic study, when the maximum EMG amplitude during automatic flexion of the foot in the presence of tibial synkinesis is twice as high as the maximum EMG amplitude during an attempt to perform isolated dorsiflexion of the foot (Fig. 2 A, B, C).
The pyramidal level of coordination matures by the age of two, and with the end of its maturation, locomotion is formed in full.
Rice. 2 (A, B, C) - A patient with Strumpel's tibial synkinesis.
A. Arbitrary isolated dorsiflexion of the left foot is minimal (within 10°). B. An attempt to bend the knee of the left leg is accompanied by automatic dorsiflexion of the foot of this leg. C. EMG of the tibialis anterior muscle during an attempt to produce maximum dorsiflexion of the foot of this leg (upper curve). EMG of the anterior tibial muscle is significantly increased in amplitude when trying to bend the knee of the same leg (lower curve).
me. Consequently, the scheme for constructing movements gives us an idea of the process of the stage-by-stage organization of locomotion, and for each level it is possible to determine a differential feature. Thus, for the thalamo-pallidar level it is a global flexion synergy, for the striatal level it is Shtrumpel's tibial synkinesis, for the pyramidal level it is an arbitrary isolated dorsiflexion of the foot. Even after these levels are finally formed, locomotion does not freeze in its development, its elements undergo changes caused by hormonal disturbances during adolescence or dilapidation, deterioration of coordination mechanisms in old age, as well as damage caused to the brain by trauma or illness. In this sense, the pathology of posture and walking in cerebral palsy can be interpreted as the result of the development of initially defective brain structures responsible for coordination at each stage of locomotion ontogeny.
Bernstein's next postulate is the principle of a reflex ring, or otherwise - feedback, or the so-called sensory corrections (sensory - from Latin sensus - perception, feeling, sensation). These formulations define the same concept.
Bernstein for the first time introduces the concept of a reflex ring as a form of feedback into neurophysiology, having entered into a dramatic discussion for himself with the great Pavlov, who built his theory of organization and improvement of function on the concept of a reflex arc, thus excluding feedback.
Movement is, according to Bernstein, two cycles of interactions: peripheral and central (Fig. 3).
The peripheral motor apparatus carries out its activities through complex interaction with the external environment. The measure of muscle tension depends both on the innervation state of the muscle and on the value of the articular angle, i.e. from the instantaneous position occupied by the system of links. It follows from this that muscle tension is one of the causes of movement, since it is a force that is applied to the link and forces it to change its position. On the other hand, the movement of the links, accompanied by a change in the articular angles, changes the distance between the points of attachment of the muscles and thereby causes a change in its tension. Here there is a cyclic form of interaction characteristic of physiology: muscle tensions affect the course of movement, and movements affect muscle tension. Such cyclic interactions are well known in mechanics and are expressed in mathematical language. Above the peripheral system of cyclic interactions, another one is built, the activity of which is also cyclic.
This is the central nervous system with all its numerous apparatuses. Here they have taecTO interactions of a different order. First of all, the primary effector impulse from the command device, directed from the CNS through the cells of the anterior horns to the muscular system, sets the latter in motion or changes the state of its movement. This movement or change in movement is perceived by the nerve windows
tendons, muscles and articular bags, which belong to the proprioceptive nervous apparatus. They transmit information about changes in movement through affector pathways. Considering this impulse, as well as visual, auditory, the CNS sends a new impulse, making adjustments to the initial motor impulse, i.e., there is a cyclic nature of interactions, which indicates a reflex ring, the presence of feedback or sensory correction.
The passive motor apparatus consists of movable bone links that form kinematic chains, which are characterized by degrees of freedom of mobility.
The transition from one degree of freedom to two or more marks the emergence of the need for choice. An automatic continuous expedient choice becomes necessary.
The kinematic chain will become controllable only if it is able to assign certain trajectories of motion that we desire for each of the elements of the chain and make these elements move along the assigned path.
“In overcoming the excess degrees of freedom of a moving organ, i.e., in turning the latter into a controlled system, the task of coordinating movements lies.” Bernstein calls the principle of coordination the principle of sensory corrections.
The foregoing fully explains why disorders in the effector apparatuses of the CNS, as a rule, do not lead to pure coordination disorders, giving only syndromes of paralysis, paresis, contractures, etc., and why malfunctions in the afferent systems necessarily cause movement disorders of the atactic type. , i.e. coordination disorders.
All forms of organic coordination disorders known in the clinic are always associated with diseases of the receptor apparatus and their pathways: vestibular apparatus (labyrinth or vestibular ataxia), posterior columns of the spinal cord, conducting proprioceptive and tactile impulses (tabetic ataxia), cerebellar reciprocal systems (cerebellar ataxia) .
In a person, compensations are possible that can overcome organic ataxia to one degree or another. They are always carried out by including a new type of sensitivity (visual, auditory, etc.) in the motor process.
All types of afferentations of the body are received in different occasions and, to varying degrees, participation in the implementation of sensory corrections.
Using the terminology of Sherrington, Bernstein calls the entire set of receptor functions of this kind "propriocepticon" in a broad functional sense.
This is a system of sensory signals about postures, articular angles, speeds, muscle stretches and tensions. The muscle, causing by its activity changes in the movement of the kinematic chain, irritates the sensory endings of the proprioceptors, and these signals, closing in the CNS on the effector pathways, make changes to the effector flow (i.e., there is a reflex ring). Coordination in this sense is not some kind of precision or subtlety of effector impulses, but a special group of physiological mechanisms that create a continuous organized cyclic interaction between the affective and effector processes.
Since every movement that has real meaning overcomes internal and external forces on its way, its whole essence lies in the expedient struggle with them.
The motor task and the forces that must be overcome to solve it are dictated by the outside world and are beyond the control of the individual.
In order to correctly solve a motor task, it is necessary to calibrate it with the help of the sense organs throughout the entire motor act, from beginning to end, to monitor and control every moment: is the solution of the problem proceeding as it should, and every moment to make the necessary corrections. The mechanism of these motion corrections is sensory correction. A defect in one or another of the most important types of sensitivity for movement and the sensory corrections they provide leads to severe impairments in motor coordination.
Movement cannot be carried out according to the internal laws of the balance of excitations and inhibitions alone, because from the very first moment it will be violated by external forces unknown to the organism in advance and beyond its control, and the forces of mutual collisions and recoil in long and mobile chains of limbs, and the resistance of the external environment. .
The role and activity of the sensitive afferent systems of the body only begins from the moment they give the starting signal for the next movement. As soon as it begins, in response to the first effector impulses, afferent impulses appear in all sensitive devices of the motor apparatus (in the organs of muscular-articular sensitivity in the first place), signaling how the movement began and how it proceeded. These test sensory signals determine the necessary next sensory corrections in the brain.
Based on this, the fundamental form of the nervous process in the implementation of a semantic motor act is, according to Bernstein, the form of a reflex ring.
When performing a motor task, sensitive systems provide two different functions: a signal-starting service and a service that controls the effect of movement and ensures its controllability.
The study of the control of integral semantic motor acts presented the afferent systems of the body in a completely different light. An analysis of the coordination construction of a motor act and its disturbances in pathology, the study of how movements are controlled in the order of a circular process such as a “reflex ring” showed that afferent systems signal the brain about the course of movement and provide the basis for sensory corrections not with “raw sensory signals, isolated from each other on the basis of quality (separately tactile, kinesthetic, visual, etc.), but vice versa. These perceptions, which provide control of movement, always have the character of entire complex syntheses, complexes of the most diverse sensations deeply worked out by the brain, fastened also by numerous traces of previous sensations, preserved by memory, impressions of previous movements in space. “The more complex the motor task, the more complex and further from the primary raw sensations is the sensory (sensory) synthesis that serves this level, the more internal brain processing, comprehension, ordering and even schematization of the primary sensations that are generalized in it.”
All successive evolutionary complication and enrichment of sensory syntheses proceeded along the line of eliminating distortions and inaccuracies of individual sense organs, ensuring reconciliation of their testimony, and understanding.
All successively formed levels of construction of movements (as the modern physiology of motor acts also designates them) have a very different evolutionary age, have been preserved in humans, having formed a whole hierarchical ladder of mutual subordination, and the topmost of them belongs exclusively to humans (the level of speech and writing) . The most ancient lower levels, formed in animals with their brain substrates and lists of motor tasks feasible for them, have been preserved in humans and continue to control the most ancient, semantically primitive motor acts (swallowing, swimming, walking, etc.).
“At the beginning of the formation of a new individual motor skill, almost all corrections are surrogately carried out by the leading level - the initiator, but soon the situation changes, each of the technical aspects and details of the complex movement being performed sooner or later finds for itself among the lower levels one whose afferentations are most adequate to this detail in terms of the qualities of the sensory corrections it provides. Gradually, as a result of a series of successive switchings and jumps, a complex multi-level construction is formed, headed by a leading level, adequate to the semantic structure of the motor act and realizing only the most basic corrections that are decisive in the semantic sense. “Under his conducting, a number of background levels participate in the performance of movements, which serve the background or technical components of the movement, tone, innervation and denervation, reciprocal inhibition, complex synergies, etc.” (N.A. Bernstein).
The process of switching the technical components of traffic control to the lower, background levels is what is usually called traffic automation.
In any movement, whatever its level height, only one leading level is realized.
The essence of the automation process, which sometimes requires a long time and persistent exercise, lies precisely in the development of the CNS plan for the above-described layout of the backgrounds, in determining the motor composition of the movement.
Determining the motor composition is sometimes referred to by neurologists as “projecting a movement”.
Initially, to maintain a stable step length, the child uses proprioceptive mechanisms and makes a “post factum” correction, then a more advanced method of “ante factum” correction comes in (from Latin post and ante - after and before the fact, respectively).
The phenomenon of preliminary corrections is in all cases a later and more perfect form of coordination than the mechanism of secondary corrections.
At the beginning of mastering the movement, the beginner strains all the antagonist muscles, disables all degrees of freedom in advance and with a margin, leaving one or two movements most necessary for this base.
At the next stage of the exercise, having already become accustomed to it, when and in what direction the next push of the reactive force will befall him, the subject allows himself to gradually, one after another, release the freedoms that are fixed to that degree in order to prevent reactive forces, which gives a sharp energy saving, i.e. e. struggles with reactive forces. In the third stage of the development of movement, the struggle against reactive forces is of a different nature, when they are transformed from hindrances into useful forces.
Sensory corrections are a stimulus both in the process of formation of movements and in the process of their further improvement in the age aspect. Moreover, Bernstein defines the process of organizing movement within his class as evolutionary, and the transition to a new class of movements, due to the emergence of a more differentiated level of coordination, as revolutionary, spasmodic. Movements of a higher level of regulation appear within the lower organized class, reach a maximum of development, and signs of previous movements that are irrational from the point of view of a new motor task are forced out.
For example, motor automatisms of global flexion synergy are gradually replaced by more localized automatisms of tibial synkinesis. At the same time, the biomechanical and electrophysiological characteristics of walking change, allowing you to perform more complex motor tasks, such as differentiation of the phases of the reference period of the step, the ability to overcome soil irregularities, a higher pace of walking, etc.
Ultimately, it is sensory corrections that solve these problems. After all, the executive muscular apparatus, all muscle work is controlled by impulses coming from the cells of the anterior horns of the spinal cord, according to the principle: an impulse is a muscle contraction. All coordination “showdowns” (with what force the muscle contracts, when, for how long, etc.) occur at the supraspinal levels - at the levels of coordination indicated by Bernstein, that is, up to the cells of the anterior horns of the spinal cord. Thus, according to neurological terminology, the “final path” is one for all the diversity and complexity of the suprasegmental apparatus of the CNS.
Posture, walking characteristics, therefore, are formed at supra-segmental levels, and sensory corrections are the instrument of this process.
This principle is very important in the sense that with cerebral palsy, i.e. with central paralysis, it is apparently unjustified to talk about the loss of muscle strength as a reason for limiting the range of motion in the joint (this is typical only for peripheral paralysis, where interrupted or the final - efferent - path is damaged), but we should talk about a violation of coordination of movements - discoordination, dyskinesia (from the Greek dys ... and lat. dis ... - a prefix meaning difficulty, violation, loss of something). From these positions, it is logical to consider the essence of the methods of orthopedic correction of posture and walking in cerebral palsy.
All the means used by orthopedics are intended to ultimately affect the nature of sensory corrections, whether it is a decrease in the flow of sensory impulses when fixing the joint with a splint or orthopedic apparatus, or the use of cold to increase the flow of impulses. The latter is achieved, for example, by the Michel La Mathieu method, when, with flexion contracture of the wrist joint and finger joints, further rather strong and prolonged flexion performed by the doctor and enhancing the afferent flow causes an increase in the volume of extensor movements. The same role is played by the so-called medical load suit - the suit of astronauts, proposed for use in cerebral palsy. With the help of longitudinal elastic bands, going from the shoulder girdle to the waist and from the waist to the feet, sensory impulses are enhanced in the coordination structures of the brain responsible for the regulation of antigravitational functions. Indeed, when using the suit, we observed a significant increase in the stability of the posture and walking of children with cerebral palsy. Although it should be noted that in this case it is impossible to exclude inappropriate biomechanical compensations to increase the stability of the posture, such as a change in the depth of the curvature of the spine, increased imitation synkinesis, etc.
Surgical intervention also significantly affects the flow of sensory impulses: myo- and tenotomy (from Greek mfs - muscle, tome - segment, tendo - from Latin - tendon; in medicine - dissection of muscles and tendons), arthrodesis (from Greek arthron - joint, de - from Latin and des - from French - absence) exclude movements in the joints and practically stop the flow of proprioceptive impulses. This explains the antispasmodic effect of operations for cerebral palsy, extending far beyond the area of intervention. Sometimes one dissection of the rectus femoris muscles with rectus syndrome normalizes the entire posture.
Muscle transplantation also changes the afferent flow, thus intervening in the mechanism of sensory corrections. This provision forces a stricter approach to indications for surgical operations in the age aspect. Global synergy, for example, makes the effect of any operation difficult to predict, as well as the combination of equinus with tibial synkinesis.
The most favorable result is in patients with cerebral palsy with insufficiency of the pyramidal level of regulation, i.e., when the prelocomotive period has basically completed its formation and we practically do not predict the result of “talamo-pallidar patients” with cerebral palsy, since the period of locomotion formation has just begun its development.
These and other complications will be discussed in more detail in the chapter on the principles of surgical correction of posture and walking in cerebral palsy.
Sensory corrections are the basis of not only the organization of movements in ontogeny, but also the mechanism for their improvement, as evidenced by the theory of skill development in sports, work, and the organization of locomotion. N.A. Bernshtein in his theory highlights the main structural components of the locomotor act: the alternation of the support and transfer periods, the period of double support.
According to the principle of equality of action and reaction, the efforts of the legs are equal and opposite to the efforts of support reactions, i.e., the force effects of the supporting surface on the body of the walker. This is the vertical component of the step (see Chapter IV).
The most informative is the longitudinal component.
The force impulses that cause the movement of the leg during walking are by no means limited to one pair of simple reciprocal impulses for each double step.
When studying the development of running in children, it was found that normally, in children from 2 to 5 years, the organization of the transfer period begins and the greatest innovations appear in the proximal points of the leg, while the distal ones remain stable for a long time.
From 2 to 5 years, the longitudinal curves of the femur show a complete restructuring of the transfer time while running, while the curves of the feet have not yet differentiated from walking even in the support period.
This prevailing course of evolution from top to bottom from proximal to distal points leads N.A. Bernshtein to the following physiological generalization. (Since this information is extremely important for an orthopedist, especially a surgeon who corrects posture and walking in cerebral palsy, it seems appropriate to quote the entire text of the author.) “It is extremely unlikely that the nervous dynamics of the distal muscles lagged so sharply (for whole years) proximal muscles. Much more likely otherwise. The proximal points of the leg (for example, the hip joint) are surrounded by a much more powerful array of muscles than the distal ones (foot), and at the same time, the moments of inertia of the parts of the link closest to the first ones are undoubtedly smaller than the moments of inertia of the distal links. Therefore, it is much easier for the muscles of the hip group to move the upper segments of the thigh from their place than the foot, for the displacement of which they have to move the entire inert leg from top to bottom. Related to this is also the fact that the (relative) velocities of the distal links are, as a rule, higher than the proximal ones. Consequently, the former have more kinetic energies and it is more difficult to overcome them. The distal links play a role in relation to the entire leg, reminiscent of the role of a heavy pendulum.
It follows from this that, given its strength, it is incomparably easier for a nerve effector impulse to slip into the proximal curve and be reflected in it in the form of a noticeable dynamic wave than to be able to break through the entire thickness of the inertial resistance of the distal system. In order to be felt in the latter, the effector impulse must have a significant strength, or else it must arrive "on time" - at a moment when the distal system is in especially favorable conditions for its perception.
It is still difficult to say how this favorable moment can be expressed, and here, apparently, a large field for research opens up: maybe it’s just the advantageous posture of the limb that matters here, which provides the muscles with the greatest biomechanical efficiency of action, maybe this favorable moment is a turning point. speed, when the inertial resistances are the least noticeable, perhaps, finally, this is the moment of a particularly receptive adjustment of the muscular apparatus, created here by one or another confluence of proprioceptive signals.
One way or another, the control of the distal links requires greater dexterity, a higher coordination technique in the sense of the ability to improve the right, optimal moment, to give just the right impulse just at the right time. If this time is missed even for a fraction of a second, then the impulse will no longer “pass”, i.e., it will not give any noticeable effect on the periphery.
It should be noted that we are not talking about small coordinated movements of the distal segments like finger movements, but about global, extensive, extrapyramidal type displacements of the distal limb segments. The dynamics of these latter ultimately depend on the same hip muscles as the dynamics of the proximal points of the leg.
But the distal dynamics becomes richly divided into biodynamic details not when these details appear in the effector impulse and begin to be reflected in the dynamics of pliable proximal points, but only when the functional attunement of the effector and receptor is established and when the effector n.s. learns to capture fleeting moments of functional conduction. Dynamic dismemberment is accompanied by a particularly large wealth of power “overflows” in the distal links, indicating a very fine control of the dynamics of the external, biomechanical order.
In a complex multi-link pendulum, such as a leg in the biomechanical sense, the dynamic interaction of the links, the play of reactive forces, complex oscillatory chains, etc., are very diverse and abundant. And the fact that they are not obscured by a trained master, but are reflected in such abundance in dynamic curves, speaks of a very fine reactive adaptability of the neuromotor apparatus to proprioceptive signaling.
A higher degree of dissection of the distal force curves is a sign of the ability to catch the moments of least resistance, in other words, to most fully utilize both the entire external rich play of forces and, possibly, the entire physiological (involuntary) range of reciprocal and other, more complex reactive processes on the muscular periphery.
This material, which is relatively difficult for the clinician, is cited to emphasize that surgical extremism in matters of transplantation and lengthening of the muscles that control movements in the joints of the feet in children with cerebral palsy is hardly justified until the walking stereotype is finally formed. It should be noted at the same time that the motor development of a child with cerebral palsy almost always lags behind by 2-3 years. If we take into account Bernstein's information, walking and running normally mature by 5 years.
Further, the author states the presence of three steps of walking involution in the age aspect.
1. Decreased function of the structural mechanisms of walking, but greater control of consciousness.
2. Wary consciousness is replaced by fussiness, small step movements.
3. Explicit disintegration of motor structures.
The splitting of the previously unified coordination is noted.
Thus, the ontogenetic material showed with certainty that dynamic structure walking arises, passes through a series of regular stages of development, and just as naturally involutes in old age.
What is most important in principle here is that this development is associated with very distinct qualitative shifts in the very structure of walking.
In terms of morphology, this structure passes in early ontogenesis through:
a) the stage of the reciprocal innervation primitive;
b) the stage of gradual development of morphological elements;
c) the stage of excessive proliferation of these elements;
d) the stage of reverse development of infantile elements and the final organization of an integral and proportionate form.
“With regard to motor coordination, the biodynamic structure of walking also passes through a number of qualitatively different stages of development: at the very beginning, there is a symptom of hypofunction of proprioceptive coordination in general, then follows the stage of development of proprioceptive coordination post factum (compensatory or secondary coordination).
Much less often, ante factum coordination develops (dosing or primary coordination), which is organized much later.
So, Bernstein's theory of the construction of movements gives an idea of the neurophysiological and biomechanical structure of the movement in the process of its formation and improvement. It includes fundamental provisions:
1. The ontogenesis of human movements repeats phylogenesis, which allows us to speak about the universality of the scheme for constructing movements proposed by the author, and, therefore, the validity of applying these laws to various disorders in the human motor sphere, including cerebral palsy.
2. The level of coordination is morphologically strictly marked and includes certain structures of the brain, afferent and efferent receptor systems capable of regulating specific classes of movements.
3. The qualities of movements are not inherited, but acquired. Improving the qualities of movement is a process consisting of stages of maturation of brain structures that coordinate certain classes of movements specific to this level. This process has a stepwise character. The totality of the complex of brain structures of coordination and the class of movements specific to it, Bernstein calls the level of construction of movements. For each class of movements, we have defined a sign - an indicator specific to this class of movements.
For the thalamo-pallidar level it is a global flexion synergy, for the striatal level it is Shtrumpel's tibial synkinesis, for the pyramidal level it is the ability to produce an arbitrary isolated dorsiflexion of the foot, an isolated movement of the fingers.
4. In ontogenetic development, nature uses all previously acquired mechanisms of coordination from primitive ones, which in humans pass into the sphere of vegetative science, to HIGHEST social actions. From each class of movements, nature in ontogeny uses the elements that are appropriate for the performance of a motor task by inhibiting movements that are not needed for a new, more complex coordinating task. This function is performed by the next, more highly organized level of coordination.
5. The basis of coordination is the mechanism of sensory correction, two cycles of interaction and the mechanism of skill development.
6. A comparative analysis of the qualitative characteristics of movements in the process of their ontogenesis in normal conditions and clinical symptom complexes of posture and walking disorders in cerebral palsy allows us to draw clear parallels. Based on this, there is reason to believe that cerebral palsy is not a disease with a residual stage, but the result of the maturation of an initially defective brain, which manifests itself already in utero. The similarity of movements of a certain class and the symptoms of movement disorders in cerebral palsy makes it possible to classify the pathology of posture and walking in cerebral palsy according to a defective level of coordination, while taking into account the sufficient conventionality of this scheme.
7. The child is normally born "thalamo-pallidar". During the first two years, he goes through two more stages of the prelocomotor period of development of coordinating mechanisms - striatal and pyramidal. In children with cerebral palsy, the pyramidal level does not reach its full maturity. The more late and with more defectiveness the maturation of the brain structures responsible for coordination takes place in this patient motor functions, the more difficult it is to predict the result of treatment and the more cautious, apparently, one should approach the appointment of radical, in particular surgical, methods of treatment.
8., The prelocomotor period completes its development by the age of 2 in the norm. This means that all the elements necessary to maintain a stable upright posture and walk are available. Nevertheless, Bernstein points out that such components of locomotion as the phases of support, elements of running, complete their development by 3 years, and all components of normal locomotion - by 5 years. Children with cerebral palsy are significantly behind in the development of motor skills - by 2 and 3 years. In this regard, it should be noted that the prognosis of any surgical intervention in children under the age of 6-7 years is difficult and the result does not always coincide with the desired one.
The main provisions of the theory of the process of life is not a simple "balancing with the external environment", but an active overcoming of this environment; the process of building movements, in which there is not only direct, but also continuous feedback between the brain and executive organs;
to build movements of varying complexity, commands are given at various levels of the nervous system. When automating movements, control functions are transferred to a lower (unconscious) level; "repetition without repetition".
Conclusion 1, movement training does not consist in standardizing commands, not in “teaching commands”, but in learning to find and transmit such a command every time, which, under the conditions of each specific repetition of the movement, will lead to the desired motor result.
Conclusion 2 The movement is not stored ready in memory, but each time it is built anew in the process of the action itself, sensitively reacting to a changing situation. The memory stores not the clichés of the movements themselves, but the prescriptions for their construction, which are built on the basis of a mechanism not of stereotyped reproduction, but of an expedient adaptation.
Movement construction levels The physiological level of movement construction is a set of phenomena that mutually determine each other, such as: a) a special class of motor tasks; b) the corresponding type of corrections; c) a certain brain level and (as a result of all the previous); d) a certain class (list) of movements.
A person has 5 levels A - the level of tone and posture; B is the level of synergy (coordinated muscle contractions); C is the level of the spatial field; D - the level of subject actions (semantic chains); E - a group of higher cortical levels of symbolic coordination (writing, speech, etc.).
The main difficulties in controlling movements are the extraordinary richness of the mobility of the motor apparatus. human body, ; the need to limit the huge excess of degrees of freedom; elastic compliance of muscle rods; many external forces that arise in the process of movement, the direction and intensity of which is difficult (and often impossible) to predict.
Motor skill formation Motor skill is such a degree of possession of the technique of action, when control is carried out with the leading role of consciousness, and the action itself is characterized by an unstable way of solving a motor task.
The characteristic features of the motor skill of movement control occur with the leading role of consciousness; lack of stability, constant search for ways to best solve a motor problem; low speed; low strength, instability to knocking factors; the inability to switch attention to the objects of the environment.
Factors of the initial ability to perform a motor action of already existing motor experience, previously developed coordinations, sensations and perceptions; the state of general physical fitness; knowledge of the technique of action and the features of its implementation; conscious attempts to build some new system of movements for themselves.
A motor skill is such a degree of mastery of the technique of action, in which the control of movements occurs automatically and the performance of the action is highly reliable.
Features of motor skills automated nature of action control; high speed of action; stability of the result of the action; extreme strength and reliability.
Phase determination of the leading level; determination of the motor composition of the skill; identification and painting of corrections; automation, standardization and stabilization of motor skills.
Stages of skill formation 1. The first stage: low speed, tension, inaccuracy of movements. 2. The second stage: the disappearance of tension, the formation of muscle coordination, an increase in the speed and accuracy of a motor act. 3. The third stage: a decrease in the share of participation of active muscular efforts in the implementation of the movement due to the use of reactive forces, which ensures the dynamic stability of movements and the economy of energy costs. During this stage, the phases of standardization and stabilization of the motor skill are realized. blocking excessive degrees of freedom of the kinematic chain. painting corrections and automation of control
§ 7. Levels of construction of movements, according to N.A. Bernshtein
The more complex (more accurate, more meaningful, more objective) the motor task, the higher the “level of movement construction” is, and the higher levels of the nervous system are involved in solving this task and implementing the corresponding movements.
N.A. Bernshtein singled out and described in detail the five main levels of building movements, denoting them in Latin letters L, I, C, D, E.
The most ancient in phylogenetic terms - level A which is called the level of “paleokinetic regulation”, or rubrospinal, by the name of the anatomical “substrates” that are responsible for building movements at this level: the “red core” acts as the “highest” regulatory instance of this level of building movements, to which other subcortical structures are also related . The system of these structures ensures the receipt and analysis of proprioceptive information from the muscles, holding a certain posture, some fast rhythmic vibrational movements (for example, vibrato among violinists), as well as a number of involuntary movements (shivering from cold, shivering, chattering teeth from fear). Level A a person almost never has a leading level of building movements.
Second - level B- is also called the level of "synergy and stamps", or the thalamo-pallidar level, since its anatomical substrate is the "visual tubercles" and "pale balls". He is responsible for the so-called synergies, i.e. highly coordinated movements of the whole body, for rhythmic and cyclic movements such as "walking" in infants, "stamps" - for example, stereotypical movements such as bending, squats. This level provides an analysis of information about the location of individual limbs and muscles, regardless of the specific conditions for the implementation of the corresponding movements. Therefore, he is responsible, for example, for running in general (say, for running in place) as a variable work of various muscle groups. However, real running takes place on a specific surface with its own bumps and obstacles, and in order for it to become possible, it is necessary to connect other, higher levels of movement construction. This level is also responsible for the automation of various motor skills, expressive facial expressions and emotionally colored pantomime movements.
Level C, called the level of the spatial field, or pyramidal-strial, since its anatomical substrate is already some cortical structures that form the so-called pyramidal and extrapyramidal systems, ensures the orientation of the subject in space. The movements performed at this level are clearly targeted: they lead from somewhere, somewhere and for some reason. Accordingly, they have a beginning, middle and end. Such, for example, are swimming, long jumps, high jumps, floor acrobatic exercises, hand movements of a typist or pianist on the keyboard, winding movements, i.e. those where it is required to take into account the "spatial field".
An even higher level is levelD, also called parieto-premotor, since its anatomical substrate is exclusively cortical structures in the parieto-premotor regions. It is also called the pre-
meaningful actions, since it provides interaction with objects in accordance with their objective meanings. Examples of movements at this level: drinking from a cup, removing a hat, tying a tie, drawing a house or a person. If we recall the structure of activity, according to A.N. Leontiev, then we are talking about the performance of actions, not operations, i.e. the goal of an action built at this level can be achieved different ways(other levels are responsible for the implementation of operations).
Finally, level E(N. A. Bernshtein said that this level is the least studied in the physiology of activity - perhaps it’s not even one, but several levels) is responsible for “the coordination of speech and writing that is leading in the semantic sense”, which are no longer united by an object, but by an abstract mission or intention. Such, for example, are the speech and other movements of a lecturer giving a lecture, a dance of a ballerina, etc. Here we are already talking about the transfer of scientific knowledge or the artist's intention, which implies an exclusively arbitrary level of regulation of unfolding actions. The anatomical substrate of movements at this level has not yet been fully studied, although N.A. Bernshtein emphasized the undoubted participation in the voluntary regulation of movements of the frontal lobes of the cerebral cortex, referring to the works of A.R. Luria.
As a rule, structures of all levels take part in the construction of human actions, although sometimes simpler movements are regulated only by lower levels. In principle, the same movement can be built on different levels if it is included in the solution of different problems. Strictly speaking, this movement will not be “one and the same” (as was shown above, even the range of arm movements of wounded fighters increases if the patient performs more significant work for him). Therefore, it is possible to change the nature of the flow of movements by changing its meaning for a person.
From the foregoing, it is clear that the concept of non-classical physiology N.A. Bernstein helps to approach the dialectical solution of the psychophysiological problem. Anatomical and physiological structures here are just tools for realizing the tasks of the subject's activity. What structures are involved in ensuring the construction of human movements depends on what place this movement occupies in the structure of the subject's activity, what meaning it has for him. Figuratively speaking, the brain and the nervous system as a whole are an instrument with which a person "plays the melodies of his life."
However, we must not forget that the structure of this instrument also deserves to be studied in psychology, since none of the mental processes that provide the subject's orientation in the world and the regulation of his activity is impossible without a normally functioning brain. Naturally, the pathology of brain activity leads to limitations (sometimes very
significant) in the formation of an adequate activity of the subject, just as a broken or out of tune instrument does not allow a musician to extract worthy music (although, by the way, N. Paganini could play on one string). Let us therefore turn to some aspects of the functioning of the brain, studied in psychology in solving various problems, and in particular in connection with practical requests to neuropsychology, one of the founders of which was A. R. Luria.