«About dexterity and its development»

 

N.A. Bernstein. About dexterity and its development.  Moscow.: Fizkultura i sport, 1991.  288 p.

 

1. p. 27. Dexterity means to be able get out (by moving) from any position, find solution (by moving) under any circumstances.

 

2. p. 38. The skeleton of the hand is an integral delicate mosaic of 27 bones (excluding impermanent, very small bone inclusions).

 

3. p. 41. The human visual apparatus consists of:
1) six pairs of muscles, providing all possible coordinated turns of eyes while following the subject;
2) two pairs of muscles that control the lenses of the eyes - the crystalline lenses ...
3) two pairs of very thin and delicate muscles that control the dilatation and contraction of the pupils;
4) two pairs of muscles opening and closing the eyelids.
These twenty-four muscles work in perfect coherent manner ... completely unconsciously and three-quarters involuntarily.
.

4. p. 42. Only for limbs and head tools we have the number of directions and types of mobility (degrees of freedom) already close to hundreds, and if you add here neck and trunk with their serpentine flexibility, the final result will be much greater.

 

5. p. 50.  Muscle tissue, in a way one expects of a tissue, consists of fine threads (so-called muscle fibers); these threads are not intertwined, but lie in parallel bundles like well-combed hair. The finest strands of the skeletal striated muscle, with the thickness not exceeding a female hair, are stretchable like rubber. Each of these threads has the ability to contract, being affected by a nerve, i.e., it becomes shorter (deviates for 20-30 per cent from the reference value) and tighter, more resistant to stretching.

 

6. p. 53. Control of movements by means of elastic rods seems to be difficult because with such a device the motor result depends not only on rod’s behaviour, but also on various side-effects beyond our control. You may pull it 10 times repeatedly in a similar way and get 10 absolutely distinctive movements  ...Control of such a system is possible, as long as there’s a sense organ with corresponding functions of control.

 

7. p. 54. Coordination of movements is nothing more than the overcoming of the excess degrees of freedom of our bodies, that is, turning them into controlled systems.

 

8. p. 54. In physiology we call the described above principle – corrections, adjusting the movement on the basis of sensory reports - the principle of sensory corrections.

 

9. p. 55.  … sensitive systems of our body are loaded when performing this or that motion, no less than the motor ones. Over all kinds of sensitive nerves: tactile, visual, nerves of muscular-articular sensitivity, ear vestibular nerves, carrying signals of sense of balance, etc., continuous corrective streams flow to the brain, notifying him, whether the movement is adequate or not.
... Each burst of motor impulses arriving into the muscle from the brain proves to be the direct cause of a new burst of impulses flowing in the opposite direction - from the sensitive apparatus to the brain.

 

10. p. 56. Muscular-articular sensitivity is, of course, the leading and basic sensitivity in the vast majority of cases of motion control. The entire set of organs, contributing to this kind of sensitivity is called a proprioceptive system in physiology. Sensitive endings of the organs of the proprioceptive system (receptors) are scattered throughout the muscular bundles, in tendons and articular bags.

 

11. p. 59. .. to look deeper into the work of a great poet, one must look deeper into the history of his life; to reach a fair verdict to a thief, it is also necessary to get involved with his miserable biography.

Everything lives and changes. The stellar Universe itself, considered to be the embodiment of eternity and immutability two hundred years ago, is actually full of life and changes before our eyes.

 

12. p. 79. … Being put to sleep or killed with any caution, any vertebrate inevitably falls down.

 

13. p. 89.  From year to year, there has been increasing amount of information about vital activity, supremely influenced by the brain: metabolism, control of physicochemical processes in the blood, hematopoiesis, ways to combat with contagious agents, etc., etc.

 

14. Стр. 99.  …old (phylogenetically) centers of the brain, still responsible for trunk control of amphibians (level A according to our designations), work to a large extent according to «old motor laws»: by exploiting of low-voltage, slow pulses, with a high degree of ancient, chemical signaling involvement, etc.

... even humans as brain-owners, with the brain, which differs from the frog's brain more than a  multistory palace differs from savage’s shack - we have the brain with separate levels  B and A, which with considerable clarity share the control of limbs and cervico-trunk muscles, and even ancient, segmental, trunk-linked level A of a human continues working  under the same ancient motor laws to a large extent.

 

15. p. 101. ... the non-stop increase of number of unlearned movements and actions is based on the same non-stop development of completely new, higher parts of the brain, mainly the so-called cortex of the cerebral hemispheres.

 

16. p. 103.   Mammals exterminated the reptiles quickly and completely (later we'll see why). Sometime reptiles existed on planet Earth and covered a significant number of orders and species, owning both the surface of the sea, and land, and air. Nowadays, only remnants of that abundance have survived, and only four orders: lizards, turtles, snakes and crocodiles, it seems they have been still getting back at winners-mammals with icy ferocity and murderous poison-the last thing what they can do.

 

17.  p. 107 – 109.  Speed of wave of electrochemical excitement that runs along the nerve – nervous impulse – varies greatly for warm-blooded and cold-blooded animals. Along the nerve of a frog impulse runs at a speed of 8-10 meters per second, and along the nerve of a cat or human - at a speed of 100-120 meters per second. It is precisely established that this rate depends only on the specialty of the nerve (motor nerve are the fastest) and on the body temperature, and not on the size of the animal. Therefore, we have reason to believe that the nerve impulses spread over the nerves of giant pangolin no faster than over the nerves of frogs, toads and crocodiles, living nowadays.

Imagine that someone bit a hind paw of a thirty-meter giant – pangolin; feeling pain, it pulled away the paw or hit offender. For the distance of pain sensation we have a paw of 6 meters, a trunk of 10 meters, a neck of another 10 meters, taken together 26 meters, i.e. three seconds at one end. Let’s put the same time for the response from the brain to the leg muscles; we need to add at least one second for the reaction of the brain itself. As a result, it turns out that it’s seven seconds from the moment of the bite to the beginning of the reciprocal movement - the time is very considerable. ... it’s not so difficult to predict the outcome of such fight.

 

18. p. 120.  Striatum - the supreme motor nucleus of the brain of reptiles - has reached its highest development and perfection, if we look at birds. Concurrently, the cerebellum, the supreme organ, controlling the postural disequilibrium and movements of one's body, developed up to a high degree of perfection. Striatum (CI level) leads the complex neural-motor system developed in vertebrates, as we have already seen, very gradually, floor by floor. These floors: the oldest of all level A, the newer, frog-dominant, the level of Pallidum B and, finally, level of striatum CI, reached its highest point in birds – together form the so-called extrapyramidal motor system (abbreviated, ems)

 

19. p. 126.  Although the anatomical maturation of the brain comes to end by the age of two years, however, the completion of motor development as a whole is still far away. It’s possible to say about full control of movements no earlier than 14-15 years of age. Up to that time, the teenager stays awkward in many aspects, gets fatigued quickly, his handwriting is very childish, etc. This clearly indicates that coordination of all parts and divisions of the brain between themselves (as physiologists say, its functional maturation) is delayed much  longer, compared with anatomical.

 

20. p. 126 – 127.  It is the motor tasks, need for movements, the inexorable vital necessity to move ever more quickly, more accurately, more dexterous - that was the main driving force in the development of the brain and its subsidiary organs almost throughout centuries-old evolution. There might the latest, relatively very short period of time, when the conditions have somewhat changed. In human, in relation to absolutely dictatorial role of his special brain, the movements lost their decisive importance and started playing a secondary role, compared with mental and labor needs.

 

21. p. 129. … the set of phenomena closely interwoven with one another and mutually conditioning each other (a new class of problems, a new type of correction, a new cerebral floor, and, as a result, a new list of movements) is called the next physiological level of movement construction.

 

22. p. 130 - 131. … the lower the animals stand on the development ladder, the more scarce, limited and vague their perception, and conversely, the perception of the sense organs of highly developed brain primarily has the capacity to greater precision, definition and subdivision. That’s why a seven- or eight-year-old student can’t read a book with standard type and needs the largest one, although his vision is sharper than that of adults.

... the higher developed brain quite differently orders and comprehends information, transferred from the sense organs. The brain not only let itself to jump into the flow of impressions, but recycles them, combines them, quickly makes confrontations and skilfully arranges useful cross-examination.

So, an experienced doctor glances over with his weak eyes of old man and recognizes old disease unerringly, just by appearance of a patient, and his students can’t repeat it with their young eyes. This comprehension of impressions is, of course, carried out completely unconsciously and in many ways involuntarily. There’s special word invented – intuition; however, it doesn’t explain anything exactly.

 

23. p. 131 - 132.   The higher the level of the construction of movements, the less raw, immediate impressions, directly coming from this or that sense organ, participate in control of movements. In their place become whole casts or ingots of sensations from the most diverse sense organs, fused between themselves to the full unrecognizability. Let’s confine this to the vision sense only, in the way it’s functioning as a human sense. If we are able to make eyes’s movements stalled that way the eyes stay completely immobile, then it would be impossible to recognize not only the distance or the magnitude, but even the shape of the things we look at. It seems to us that we see, directly perceive through the eyes, both the distance of the object from us, and its actual size and shape, whereas in fact those sensations that inform us of these properties of objects by no means have the visual origin. We estimate the distances to visible things by feeling the tension of the eye muscles, which is required to make the images of the subject in both eyes cease to double and merge into one; we can’t feel it at all with one eye. We determine the size and shape of visible objects, because we look around the outlines, moving point by point to center of the mesh shell of the eye— into the so-called central fossa, and at the same time, again, the muscular feeling tells us how big or small the object is and what outlines are, according to the diapason and character of eye movement, required for such scanning. Sometimes we unconsciously help ourselves, at the same time touching the object.

... In control of many human movements, especially the movements of hands ... the most important and dominant place is occupied by precisely these merging, synthetic, as they are called, perceptions of space, distance, size and shape of objects.

 

24.  p. 136-137. ... there’s no neuro-motor impulse from the brain aimed directly into muscles;….

Nerve fibers, strictly insulated, extend from the brain along spinal cord to one or the other height within it, so that their branched endings fit closely to the spinal cells-keys. The motor impulse from one or the other floor or levels of brain runs down the spinal cord and excites the starting cell of that number of the myion that must be used. There was a time when in less developed vertebrates, the spinal cord possessed a decent share of independence. ... All that changed a long time ago in higher mammals and humans. The spinal cord never performs any independent movements in healthy conditions. All the control of movements had  went from it to the top, to the motor centers of the brain.

 

25. p. 139.  The tone level (A) ... in a far predominant number of movements, he gives way to the leading position to younger ones, but does not fade away completely. On the contrary, it’s hard to find a movements where the functioning of this background of all backgrounds would not underlie the movement. The fact that this functioning is not obvious is quite compatible with the role of this level as a deep foundation of movements…

... In more or less pure form, it acts as the leading level in those fleeting fractions of a second, while the flight phases of some (but not all) types of jumps last: a starting jump and jump from a water tower, ski jump from a springboard, etc. This rarity of his appearances as an instrument, performing solo while the rest of the orchestra keeps silent, has been explained with its extreme antiquity.

Level A and the movements it performs are the most solid documented evidence of our direct origin from the mother-fish, the oldest of vertebrates. The rarity of his speeches in the main parts is directly related to fact that a person find himself in a fish position only in very exceptional cases: in a position of equilibrium with the environment, beyond the tangible action of gravity. Obviously, this can happen only in rare and brief moments of the so-called free fall states. ...
The level of A ... appeared before the formation of the limbs, and naturally specialized in the musculature of the trunk and neck. He remained the same trunk and neck-cervical up to humans, while the newer levels, starting with B and above, took over a new formation - limbs

 

26. p. 141. According to the most crude scheme, levels A and B have divided the territory of the body among themselves in such a way: level A got the trunk and support, level B got the thrusters (limbs). Of course, this division is very simplistic, primarily because higher, cortical parts of the brain dominate the work of both levels. But, in addition, this division of labor was complicated by the inevitable mutual interference. Level B needed to participate in the work of trunk muscles, because old and weak motors of level A couldn’t control  powerful and fast movements of the whole body and lagged behind the limbs. On the contrary, for level A there was found so important and responsible application in the control of limb movements, that he firmly went out there on prominent roles, but only as a background level.

 

27. p. 145.  Stooped, bent figure, flabby muscles, hands, sagging along the body, like linen on a rope, easily advancing dizziness –  here, perhaps, in a somewhat condensed paints that's what happens in case of a disadvantage with level A, even without any irreparable, anatomical brain damage.

 

28. p. 146. .. the actions of level A - both in the role of the leader, and in the role of the background - are almost completely involuntary and escape from our consciousness to a large extent. He is deep down, in the holds of the brain, and it happens rare for us to go down there to survey and check his work by conscious observation. Usually it justifies the trust well, it does not like the interventions and does manages without them, as the internal organs of the body.

 

29. p. 146 – 147... With the level of musculo-articular ties, otherwise - the level of synergy,
assigned letter B, the reader has been already familiar. This was the level, developed to serve a variety of locomotions on the land, and then in the air, when the vertebrates needed. It is a contemporary and partner of their limbs. At last, it’s the first level of construction in vertebrate animals, which used frequent chains of pulses (50-100 per second), the so-called tetanus, for long and strong contractions of striated muscles of the body.

30. p. 147. In the history of the brain development, one steadily continuing process, called encephalization, is very clearly manifested. It means that as new floors and superstructures appear in the brain, one after another, functions that used to live in the lower and older parts of the brain, migrate to these structures.

 

31. p. 148….much of what for many millions of years was an inalienable property of level, went «up». It is still a level of synergy and musculo-articular ties, but not the level of locomotion, as it once used to be. We find him in human on very, very responsible background roles, but a significant portion of those items, determining its leadership even in the lower reptiles, have moved upward, into more modern and finely-equipped sections of the brain. We will find them all in the following sections, under the letter C.

 

32. p. 148.  Motor nerve cores of level B, the so-called pallidums, or pale balls, are in the very depth of the brain. The outgoing motor nerves wire no further than 2-3 centimeters downwards, to the so-called red cores, ...                                                                                                                    These red cores are the executive nerve centers of the lower level A; regardless of their independent functions  in conformity with this level, they are under additional duty to re-send pulses of B level down to starting cells. Sensitive (receptor) centers of level B are the largest of intracerebral cores ... thalamuses. It’s suitable for thalamus to be called nerve centers. They accumulate body’s nerve-conducting pathways of the whole spectrum of tactile sensitivity with its multiple subunits: a feeling of touch, pressure, heat, cold, pain, etc., and the whole spectrum of joint-muscular sensitivity .. (proprioceptive) from all points of the body, without exception.

 All these nerve pathways come to the thalamus directly from the sensitive nerve endings in the skin, muscles, tendons and joints, without any interruptions or intermediate stations. Therefore, the thalamuses receive all the sensitive signaling the most direct and fastest way, we say, firsthand.

33. p. 149-150. …there’s no level, including  level A, already described, none of the subsequent new ones, has the ability to manipulate with such vast, comprehensive synergies, as level B, being described now. Such movements as jogging, jumping, somersaulting, exercises with special sport equipment , wrestling, swimming and so on are possible only thanks to the wealth of information collected by the thalamuses. The inexorable encephalization impacted level B. … Contact sensitivity, touch, pain, joint-muscle feeling likewise broke their way into the cortex  and established large representative offices there, but they still maintained a close connection with the main cores of the thalamus, where signals come in first on their way from different points of the body. As for the long-range receptors, thalamuses of the higher mammals and humans are strongly blind and deaf. This migration also explains the depletion of movements list, independently carried out by level B. It retained the most influential position as a background level; you may see that at least based on the newly made cursory list of movements with large synergies, which are necessary interested in it, but, with its blindness, it lacks much to be a level-leader

 

34. p. 151. … due to the close connection of level B with the receptor system, the movements under his control are always monolithic and well-tuned. They look gracefully even for completely non-graceful people.  They are perfectly established not in a given moment only; the same level masterfully organizes movements in time, controls the rhythm of movement, provides alternation of the muscles-flexors and -extensors, etc. In addition, it’s very typical for B-level-driven movements - they are extraordinary identical (as if minted), being rhythmically repeated (the so-called cycles). The successive steps in walking or running are the same, like coins of the same coinage: successive cycles of movement when working with a saw, file, scythe, hammer, etc. are much more similar to each other than two drops. This property is very closely related to the formation of motor skills and with the automation of movements ...

 

35. p. 152-153.  In movements such as walking, running, etc., this level (B) does the same as a flight mechanic on airplane: it monitors the correct operation of both the main driving motors, and all auxiliary mechanisms on board, and all control devices etc. The role of  leading  level in walking or running (this is level C, as we see below) is the role of the pilot, driving the airplane along the required course, aligning it with swings, air pockets, wind changes, etc., not taking care about accidents inside the airplane. Level B is invaluable for internal control, when any of the higher levels takes over its piloting.

As a destined  background  level, it works for the most part without attracting consciousness –generally, it’s the fate of all backgrounds. Much  in its actions happens involuntarily, completely or to some extent, although they are incomparably more accessible to arbitrary interference than deep, subterranean, tonic backgrounds from level A.

 

36.p. 154. Level B in human is well suited to assimilate life experience, to build new coordinations and store them in the treasury of motor memory.
By mature age, level B is overwhelmed with all sorts of backgrounds, developed by him at the request of higher levels, that required these backgrounds as the skills developed. These backgrounds by request are what we call automatisms.
... it’s much easier for a person with a well-developed collection of backgrounds in a B-level to find a motor way out of any position without delay. And this ...is the initial and most basic definition of dexterity.

 

37. p. 154 - 157. After all this, the reader will no longer be surprised, having seen the list of independent movements, that are ongoing at level B, seemed to look like a tree in autumn. The greater part of that motor layer, it once was responsible for, transferred to the higher parts of the brain. What kind of independent movements are available now?

Semi – involuntary, semi-unconscious motor acts in the predominant part – it’s more than secondary acts for life importance. Facial expressions remained at its disposal. Pantomime, body expressions, those expressive involuntary gestures, accompanying  speech and all behavior, what restrained northerners are relatively stingy with and what comes supersaturated in life of temperamental inhabitants of the south…finally, from the same group of movements remained plastics; not the movements of Western European, ballroom dance or folk dance, rather close to the locomotion acts, but the dance movements of the lazy East…

... Next there will be movements of endearment, tenderness, realized passion; movement of the expansion of  body, sipping, yawning; some of the free-body movements in the spirit of Mueller; finally, a number of familiar, each person's own, semi-machine gestures like scratching behind the ear, spinning the buttons, playing with fingers ... and so on. (this last group of gestures is, in essence, very close to wagging the tail of the quadrupeds). That's more or less everything that level B can show us. A completely different picture is obtained when we take a list of his background performances. Here level B transforms and shows itself in all the splendor and diversity of its talents.

38. p. 157 - 158. It is not so easy to unravel level C and comprehend it in the human at first sight. This level is much more complicated than previous ones by structure and gives the impression of some kind of dual, double. He has two heterogeneous and not connected with each other systems of motor nerve centers in the brain and two no less different sensory alarm systems. It looks like it completely occupies two floors in the brain: meanwhile  this is, without any doubt, one level, rather than two separate, and the level is very cohesive, one-piece, revealing extremely characteristic, nowhere more repeating features. As for this duality, the matter is solved simply after careful analysis. We find the C level in the human in a transitional state, in the midst of the encephalization, on which we have already made some references. He is just now leaving the upper floor of the extrapyramidal motor system (emf) - the floor of the striatum we have already known (in birds), where it lived completely until the formation of a pyramidal, new navigation system in mammals. It started this relocation to another apartment so far that there’s no doubt regarding new address: all the lower sections of the cortical motor system - pyramidal (pds) - have already been fully mastered by him. Half of the property and furnishings are still at the bottom, at the old hearth, half are placed along the spacious living space of the front central gyri of the cerebral cortex.

…in 100-200 thousand years, no doubt, the human level C will become finally cortical, pyramidal, and the striatums will most likely be at the disposal of the level of musculo-articular connections (B), to which they will provide the best, finer and more perfect  functions than those that available to him now.

 

39. p. 160 - 162.  The spatial field is, firstly, exact objective (that is, corresponding to reality) perception of external space in the cooperation of all sense organs, based on all previous experience, preserved by memory.

Secondly, it is a kind of possession of this external surrounding space. Without any difficulty and thought, we can hit the finger to any point we see in front of us or clearly imagine. This means that we are able to instantly include in the work the combination of the muscles of the hand, in that strength and consistency that are necessary for an immediate and sure hit to this point. Of course, this ability to instantly translate from the language of idea of the point of space to the language of the required combination of muscles (as they say, the muscular formula of motion) applies not only to the hand and finger.Just as easily, without hesitation, we get into the same point of space with the tip of the foot, nose, mouth, etc., it is not harder to do this with the end of any object, which we hold in our hands or in our teeth.  With a slightly higher dexterity, we can get to any target point by a meticulous throw. This is what we called the possession of space - the second defining feature of the spatial field.                                                                                                                                                                               One can’t ignore a few basic properties of the spatial field, which are very important for understanding... First, it is the field of space where we own in specified sense every point, is extensive, extends far in all directions from our body. Secondly, we perceive it for sure as somewhat unmovable. When we, for example, full turn around, it does not seem to us for a moment that the whole world turned around us, although the raw, immediate sensations of all the senses tell us exactly this. Of course, we attribute to painful violations of the normal operation of the level of space those cases when it begins to seem to us that we are not turning, but the outside world (for example, dizziness). Third, we perceive the external space as completely homogeneous, identical in all parts. We all know that our eyes depict all subjects in perspective: closer ones as large, more distant as small; parallel rails seem converging to one point on the horizon, etc. Both for our sense of touch and for the musculo-articular feeling, different points of space are certainly unequal: the skin alternates strongly and weakly sensitive areas, with densely or rarely spaced tactile points; muscle feeling also has a varying degree of receptivity (depends on the position of the body or limbs, etc.). Nevertheless, despite all this, the internal processing of these raw impressions in the brain is so deep that when the integral and cohesive perception of the spatial field reaches our clear consciousness, all parts and pieces of it become homogeneous as in a geometry textbook. All those numerous distortions of reality, contained in the direct testimony of the senses are being extinguished, eliminated and straightened so completely that we are not aware of many of them. Many of these distortions of reality (so-called sensual illusions) were discovered only over the last century – in such a full manner the re-written mapping of the spatial field is able to get rid of all that; in this form, it gets into our consciousness and manipulates the corrections of the C level.
We should add to these three most important properties of the spatial field - vastness, immovability and homogeneity - the fact, that we clearly perceive the size of objects in the field and distance between them, shape of objects, correctly estimate the angles and directions, recognize and reproduce the movements (for example, depict similar figures and shapes)

40. p. 162 - 163.  Here, in this spatial field, the movements of the level C unfold.
.... Targeted movements meaning displacement of object are typical movements of the level of space. Many of them are single-passed. They always lead from somewhere, to somewhere and for some reason. They carry the body from place to place, overcome the external force, change the state of thing. These are the movements that show something, take, carry, pull, lay, throw something. They all have start and finish, an attack and an outcome, a swing and a stroke or a throw. They certainly lead to definite final result.

Even in cases where the movements are repetitive (for example, clogging of a nail, unfolding cards on a table, catching flies), this repetition, referring only to the external design of movements, always leads to clear targeted final: sooner or later  the nail will be tough hammered, all cards putted out and flies caught. It is worth comparing this property of level C movements and typical features of previously described level B: is it possible to talk about the target result of a smile or about the ultimate goal achieved by yawning?

The second trait of movement ... greater or lesser degree of accuracy; in any case, the quality assessment of the movements, corresponding to this level directly depends on accuracy…

Look again at level B: what kind of accuracy might be when frowning brows or when a child caressing his mother?

 

41. p. 163 – 164. Take a small object few times in a row, for example a box of matches, from the same place. Do this with quick and accurate movements and try to watch them . If you are afraid that watching yourself can distort your movements, make the same observations on another person without telling him about the purpose of the experiment.
You will certainly make sure that the ends of all the movements you repeat - the moments of touching the box - very accurately converge in one place, as the rays of light gather in focus. The same ways of moving the hand from the initial bent position to the goal will all be unintentionally different, diverging from each other by more than a dozen centimeters. The immediate cause of this fact is easily guessed. The responsible, semantic part of the movements is their end, when you take the box. Corrections of level C, leading these movements, maintain close oversight over this part. Intermediate, middle parts of the movement don’t matter for the result – and the leading level remains completely indifferent to them.

 

42. p. 164 – 165. …. a huge, accumulated day after day, during the whole life, experience   had developed the skill of rapid and error-free translation from the language of space points into muscle formula for movement to get to this point… Thanks to this experience, processed and absorbed by hemispheres, we achieved complete interchangeability of all movements leading to the same spatial goal long time ago.

... This property consists a significant difference between the behavior of corrections at B and C levels. The level of musculoskeletal linkage (B) always bases on one's own body. Its sensitivity continuously and in detail informs him of the positions of body parts, the strains of individual muscles, articular corners, etc…it is strongly conformed with biomechanical aspect of the movement; it keeps the most convenient and economical order while muscle activation, cares about the choice of the most smooth and streamlined motion path from myriad of possibilities, provided to him by multiple degrees of freedom. That is why his movements are usually look so coordinated, even elegant.

Level C is not such one. It bases on the spatial field, on the mark of one or another desired point of space that spreads out before the eyes.

Corrections of level C, directing the movement, are watching only for fitting into this outer space, alien to our body. What will be the character of biomechanical side of the movement? Which way the position of the joints change, even if the intermediate postures of the acting limb are inadequate? – no matter for level C

... Perhaps, this is precisely the reason why movements look so awkward and dry, being performed by C level.

 

43. p. 165. If, when moving, any unforeseen difficulties arise, the C level immediately mobilizes its wide opportunities (there’s a plenty more to choose from). At the situation that the level of the musculo-articular connection is at an impasse  (with its hammered formulas of movements, perfectly fitted to the properties of muscles and manners of joints ) there the level of space jokingly will show all its adaptability and resourcefulness. So, one can clearly see the third characteristic feature of movements of the space level: switchability. It is equally easy to get to a given point of space not only with different movements of one limb, it is just easy to do with right or left hand, elbow, and with the tip of a foot ...

 

44. p. 172 – 176. The level of action (assign it the letter D) differs sharply from all those levels that were described earlier on the basis of a number of attributes.                                                                                …the earliest rudiments of its manifestations are found only in the most developed mammals: a horse, a dog, an elephant. Monkeys have them noticeably more, but even for them the set of actions is so short and they are so rudimentary, that it’s possible to call level D rightfully and without stretch the human level.

Actions are no longer just movements. For the most part, these are whole chains of successive movements that collectively solve one or the other motor task. Each chain consists of different motions that follow one another, systematically approaching us to the solution of the problem. All movements - the links of such a chain - are related to each other by the meaning of the problem being solved.

... Try to watch for a person, who lights up a cigarette five or six times: no matter how simple this action, no matter how it is automated by the old smoker, in none of this half dozen repetitions neither the list of movements, nor their number will repeat exactly....                                                                                                It is obvious that if behind the movements, from which the semantic chain of action is composed,there is something more than simple movements and displacements of things,then among the intermediate movements of such a chain will often come  such,which move the thing not at all not where it will eventually , after the solution of the problem.  If, for example, you need to unbutton the belt, fastened with a hook, you first need to tighten the belt even tighter to remove the loop from the hook

 

45. p. 178. The level of space (C) is situated by half in the cerebral hemispheres, but, no doubt, it felt quite well at his ex-residence, in the extrapyramidal system... As for the level of action (D), it is connected with the cortex of the hemispheres completely inextricably and, apparently, simply could not exist without it....

 

46. p. 178 - 179. …human hand as a working tool is so rich in mobility ... and so well adapted to the most delicate working actions of every kind, that, naturally, the D level prefers it to all other parts of the body as an executive tool. Here is no doubt that the development of the level of action (D) with its requirements and requests has urged and directed the development of human hand. In it’s turn, the hand, distancing itself from the former paw, spurred and encouraged to improve the level of D.

 

47p. 185. You can meet persons, for example, with upper level (C2) that works perfectly while its level of the musculo-articular ligament (B) is very lame; in others cases, on the contrary, the (B) level may be remarkably fine and obedient, and at the same time it the levels C or D are quite dysfunctional.

 

 

48. p.195-198.       Formation of movements in adolescents.

 

In the third section of article IV, in review of the development of child movements, we stopped at the age of two. (19. p. 126.) The fact is that by this time, as it was said, the maturation of all the motor parts of the brain and their conducting nerve pathways is over, and then a long work of adapting to each other all levels of construction and the deployment of the opportunities, built into them, begins. Of course, it is not possible to characterize the harmonization of level-based actions before the levels are outlined, that’s why the characterization of this, we say second childhood, had to be postponed. Now we can shortly fill the missed, noting some of the most significant features of the development of child's motor instruments between two and fourteen to fifteen years-the age of final maturation. The development of the motor area, the so-called motor function of the child does not go along a smooth, ascending line. As in many other areas of development, it’s possible to observe sometimes stops, sometimes, or, on the contrary, quick leaps, sometimes,  sometimes even as if  retreats back. This comes out especially brightly in the age, immediately preceding puberty. At this time, adolescents are made clumsy, baggy, slow, they break and drop everything, break dishes and wipe shoes. We will soon see that this is only seeming digressions. And at the end of the second, and throughout the third year of the child's life, the final ripening of the higher motor systems still lasts. It is the period when child starts immensely increasing both the quantity and the quality of actions, corresponding to level D. The considered age is the time when the child finally ceases to be the supreme monkey and for the first time masters such actions that are completely inaccessible to the monkey. From the field of substantive actions child learns something from self-service (undressing, washing, eating with a spoon), successfully plays with toys, builds bricks and sand pies, begins to pencil something. At the same age, and precisely on the listed actions, the disparity between two handles of the child is revealed, that is, whether he is going to be right-or left-handed. At the same time, a coherent speech correctly constructed of small phrases appears, not just scattered words, as it was before. The next period, from three to seven years, is a period of predominantly quantitative strengthening and adjustment of all levels that the child has had. Anatomically, all of them are formed by the third year and ready to be filled with content.                                                                                                                                                                                        We have already seen in the feature article, devoted to levels, that the higher and newer the level, the more complex the structure of movements under level’s control, and the more the number of prepared backgrounds it needs. You can compare the levels of construction with vessels of increasing volume, which are filled longer, if more capacious. Hence it’s clear that although between three and seven years child can already use any of the human levels of movement construction, in fact he applies mostly those simpler ones that had been previously filled with some content. For the most part, these levels belong to extrapyramidal motor system (ems), limited by striatum sublevel, i.e. the lower sublevel of space C1, sublevel of locomotion and gymnastic-like gestures.  In contrast to children of one and a half - two years old that are similar to laggard teddy bears, children from three to seven are graceful and mobile. They run well and fast, they jump and climb. They have already developed a sense of rhythm, they are excellent at coping, for example, with jumping through the rope their partners twist. They have a variety and emphatic facial expressions and, talking about anything, they gesticulate animatedly and convincingly. They are very good at imitative reproduction of another's movements also: when they play kings, it is always easy to guess on gestures of such kid, what activity he represents; in caricature mimicking of motor lacks of his companion he is capable to reach cruel virtuosity. However, as soon as you try to force to do such a child for some activity in the sub-level of accuracy C2, or even more in the level of action D, weakness and fast fatiguability are immediately revealed. The notorious restlessness of a child of these years depends not only on his particularly strong need for movement: in a sitting position, he doesn’t have available and feasible pastime, so he has nothing to occupy himself and he immediately gets bored

Professor . M. Gurevich aptly points that child's brightly conspicuous indefatigability is only seeming. After all, almost all the movements he produces are free movements, without load, without work in the literal sense, movements that do not overcome any resistance, and therefore do not require any special expenditure of energy. We have already talked about the elegance of movements, generally inherent in the level of musculo-articular ties, and the reasons for this elegance. This level delivers the most important backgrounds to a child of the described age. The next period of motor development covers period from about 7 to 10 years. By this time, the upper, pyramidal, sublevel of space C2 is being gradually filled up with working backgrounds. The motor means of a child gradually includes two new components - strength and accuracy.  This puts its imprint on both the child's games and his work to which they begin to attract him by this time. With no idea about the theory of movements, which has been developing in scientific thought only in recent years, life practice very sensitively caught the age, when it already makes sense to accustom a child to some sort of labor skills. This is just the age of transition into the working state of child’s pyramidal motor system (PDS). Although a child is not yet capable of prolonged attachment and focusing on for these years, small and precise movements are starting to develop and he has something to do, sitting at the table. 

His handwriting, at the very beginning of training consisted of letters with a walnut size, turns to be smaller and smoother, the pen presses do not pull out more lines, thick and pasta-like, and he already breaks his feathers less than twice a day. Boys improve their throwing and striking movements (not without reason, the most important fights and the maximum of bloody noses and broken glasses falls precisely at this age!) and develop the dexterity of the throw.  It is self-evident that, at this junior school age, it is necessary to begin education and training precisely according to the skills of the upper sublevel of space C2: hits- and throws movements, that required accuracy and just mentioned, precise movements in the space, etc. Teachers, who start teaching a child to play the musical instrument at this age, are doing the right thing. After the age ten - eleven, here’s a period of a large and complex alteration, embracing all life aspects of a growing organism. This is the age immediately preceding puberty, and the period of maturation itself, until the completion, i.e., up to 14-15 years. It is not so easy to characterize it. On the one hand, levels of construction persistently continue to be enriched and filled with skills and backgrounds. Finally, the level of action that the entire first decade of life had to merge with the content of the first group of our classification - actions without backgrounds, begins to receive at its disposal the first higher automatisms - the basis of skills of all kinds. At this time, it is possible and necessary to teach a child for manual labor. It is easy to awaken the taste for action at this time, desire to handmaking and if you catch interests and inclinations of a child, you can achieve a lot. On the other hand, the harmony and agreement between the coordination levels, as if achieved, come to disagreement in many aspects, this time not at the fault of the levels. They reflect tremendous shifts in the work of all glands of the body, its complicated internal chemistry.  This restructuring of the whole metabolism, switching of all discharges in the organs of the body is experienced by the body as a shock - work , to which all other current actions are sacrificed. This is mainly the cause of awkward and baggy looseness of movements, of slowing down of motor reactions, of temporary sharp decrease in agility and even strength. It is well known that in this period the mental life of a teenager often undergoes a serious disintegration, sometimes turning into real nervous breakdowns, completely eliminated in the next period of life. Precisely because transient disturbances of movements are not associated with any disturbances in the motor system of the brain - that's why one should not be embarrassed by the youth's motor awkwardness and shouldn’t stop their training of motor skills in work and sports. On the contrary, if only in this or that particular cases there are no direct contraindications for this, for example, expressed by the doctor, it is especially important to actively educate the levels of construction during this transition age, both upper and lower. Such systematic work upon them, within the framework of the order and regime, will lead nowhere, but to the most beneficial effect on the motor field, and on the mental life of emerging human.