DVIZhENIYa (in biology)

From Big Medical Encyclopedia
Revision as of 23:16, 13 April 2016 by Doctordss (talk)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

MOVEMENTS (in biology) — one of manifestations of life activity providing a possibility of active interaction of components of an organism and the whole organism with the environment.

Are presented in various forms of interaction of an organism with the environment, the interconnected processes proceeding in internal environment at the cellular, fabric, organ and system levels.

So, smooth muscles provide a tone and wavy reductions of blood vessels, a stomach, intestines, uterus, etc. D. of liquids in an organism (transport of blood and a lymph on vessels, movement of an interintercellular lymph) provides processes of digestion and absorption, optimum level of a metabolism.

Activity of all these mechanisms is directed to preservation of a homeostasis of internal environment of an organism (see. Homeostasis ) and stability at expansion of the processes proceeding in bodies and systems.

Emergence of physiology of D. as the section of general physiology studying mechanisms of activity of skeletal muscles, as a result a cut D. are made, it is connected with emergence in 19 century of various ways of its registration with the help sensors (see) and photos [E. Marey, Maybridzh (E. Muybridge)]. The beginning fiziol, researches D. of the person is the detailed studying of walking which is carried out by E. W. Weber and V. W. Weber. On development of physiology of D. considerable impact was exerted by discovery of effect of electric irritation of various sites of bark of hemicerebrums [Frich and Hittsig (G. Fritsch, E. Hitzig)], to a possibility of implementation of D. the animals deprived of hemispheres. Bigger value had identification of postural reflexes of Ch. Sherrington, studying of reflex mechanisms of regulation of a pose and the balance which is carried out by R. Magnus. Serious impact on understanding of physiology of D. was exerted by N. A. Bernstein's ideas of D.'s coordination and R. Granit's works about the central regulation of proprioceptive devices.

Characteristic of the majority of animals and the person, represent result of reduction of the skeletal muscles providing maintenance poses (see), movement of links or all body in space. Function of sight, a mimicry, the speech are provided with specific forms D. At D.'s classification consider character of the reached position of parts of a body (e.g., bending, extension, etc.), functional values D. (e.g., approximate, protective, etc.) or their mechanical characteristics (e.g., rotary, ballistic, etc.).

In modern physiology the great value began to be attached to a factor of activity in behavior not only the person, but also animals. At the person D. are controlled continuously by all activity of a brain directed to performance of this or that task and modelled in consecutive muscular contractions. This form of activity call any, or conscious, D., and the coordinated activity of various muscular groups at implementation of muscular skill — coordination of. Coordination of movements is important for manifestation of dexterity, force, speed and endurance of the person and their interrelation.

Motor reactions happen simple — - bezuslovnoreflektorny reactions on painful, light, temperature and other irritants and difficult — a series of the consecutive movements directed to the solution of a certain motive task (see. Motor reactions ). The movements of the skeletal and muscular system providing movement of the person in space (e.g., run, walking, etc.) can be an example of the last locomotions, i.e.

Process of formation and regulation of motor reactions is connected both with peripheral, and with the central physiological mechanisms.

In spinal cord (see) there are neural ensembles consisting of motive units — motor-neurons which activation causes a number of rather simple reflexes: flexion, chesatelny, etc. At the level of a spinal cord also reciprocal (response) relationship of antagonistic muscles is provided. The coordinated function of motor-neurons is reached as due to reflex afferent regulation, and own mechanisms of a spinal cord (presynaptic braking, returnable braking etc.).

In a trunk of a brain accurately differentiated educations are had: the olive, a red kernel, black substance, vestibular nuclei playing an important role in regulation of a muscle tone, pose and organization D. (see. Motoriums, ways ).

The reticular formation of a trunk of a brain can carry out both the diffusion activating and brake influence, and the differentiated control of motor activity. These influences on the ascending and descending ways reticular formation (see) come as to the motive area of bark of big hemispheres, and to motoriums of a spinal cord.

Diencephalon (see) plays an important role in regulation of difficult motive acts. During removal of a thalamus (see) a physical activity of an animal becomes primitive. Hypothalamus (see) participates in vegetative ensuring numerous somatic functions, including and.

The facts showing deep and dynamic interrelation of function of the skeletal and muscular device with all system of vegetative processes allowed to formulate ideas of phases of metabolism in the developing organisms of an animal and the person that opens a special role of muscular movements in their formation.

Basal kernels (see) are the highest nadsegmentarny device of a brain trunk participating in regulation of. They provide regulation of motive acts with participation of various muscular groups.

One of the major functions cerebellum (see) it is connected with ensuring accuracy of movements, coherences of bystry (phasic) and slow (tonic) components of motive acts. A cerebellum together with a sympathetic nervous system (see. Autonomic nervous system ) exerts trophic impact on skeletal muscles, increasing their working capacity.

In bark of big hemispheres of a zone of motive and tactile analyzers take place in pretsentralny and postcentral areas (somatosensory bark). Motive and sensitive zones of bark of big hemispheres have the somatotopichesky organization; to each muscular group there corresponds a certain site of these zones of bark. The similar interrelation allows to carry out precisely D., correlating them to parameters of the environmental factors operating on an organism. Motive and sensitive zones of bark form uniform system, by means of a cut work of underlying nerve centers will be organized and regulation of a physical activity of the person and an animal is carried out. The management D. can schematically be imagined as follows. Tasks and the purpose of physical action form thinking that defines an orientation of attention and efforts of the person. The thinking and emotions accumulate and direct these efforts. Mechanisms higher nervous activity (see) create interaction psikhofiziol, mechanisms of management D. at various neurohumoral levels. Fiziol, systems on the basis of interaction of efferent and afferent bonds provide expansion and correction of a physical activity and recovery. Plays a comprehensive role in expansion of all processes connected with D.'s implementation internal environment of an organism (see). Information on results of action provides correction and efficiency of.

Depending on D.'s character fiziol, mechanisms are connected with any regulation of D. or are independent.

Control D. of skeletal muscles at implementation of motive acts is exercised on the basis of interaction of various departments of c. N of page (spinal, bulbar, srednemozgovy levels, cerebellum). At the same time the leading role is played by bark of big hemispheres, especially at difficult D.' commission the person, on the basis of mechanisms of uslovnoreflektorny bonds and at interaction of the first and second alarm systems (see).

The big role at education and implementation of movement skill is played analyzers (see). Proprioceptive the analyzer provides dynamics and interrelation of muscular contractions. He participates in the space and temporary organization of the motive act (see. Proprioceptors ). Vestibular analyzer (see) interacts with motive during the formation and implementation of movement skill, at change of position of a body in space. Acoustic analyzer (see) provides the rhythmic organization of muscular contractions, and visual analyzer (see) — space dynamics of muscular activity. All types D. inherent to a live organism and defining its life activity, proceed in unity and fight of opposite processes of an expenditure and recovery of bioenergy and structural potentials of an organism. I. P. Pavlov for the first time specified that process of braking promotes recovery of the spent razdrazhimy substance.

In live organisms process of recovery is connected in most cases with mechanisms of self-control at the system, organ, fabric and cellular levels (see. Self-control of physiological functions ). The expense is a natural stimulator of recovery and, therefore, a functional overload — an important control facility processes of recovery.

Distinguish several types of recovery: periodic, connected with biorhythms in a human body and an animal; at the same time interaction of endogenous and exogenous rhythms (change of day and night, seasons, etc.) exerts deep impact on this process (see. Biological rhythms ); preworking, arising on the mechanism of a conditioned reflex during a prestarting state and characterizing «readiness for action», according to F. A. Bainbridge, or «the warning readiness», according to A. A. Ukhtomsky; flowing — proceeds in operating time due to regulatory coordination processes and adaptatsionnotrofichesky influences of c. N of page; postworking, connected with development of brake processes in c. N of page and elimination of the changes in chemism of internal environment of an organism which arose in operating time; during postworking recovery the constructive period forms, during to-rogo there is an accumulation of structural and bioenergy resources — so-called super recovery.

Stability characteristic and D.'s reliability at different degree of functional activity of an organism, and also adaptive and compensatory systems is an important basis of life of an organism as whole.

Reliability is defined by a number of features in structurally functional hierarchy of systems of regulation of D. at all levels.

Various compensatory processes (see) are an important basis of stability and reliability of all system D. in a human body and an animal. Various regenerative processes, introduction to a system of the fabric units which were not functioning earlier, activation of function of one of pair bodies, intrasystem compensation of function concern to them. It is widely developed as well intersystem compensation of motive and vegetative functions that is especially shown at long and hard mental and physical activity.

Compensation is followed by the following sequence of processes: the alarm system about existence of defect, development of compensation at a continuous return afferentation, mobilization and improvement of compensatory mechanisms, relative stability of the arising compensatory adaptations.

Functional activity during the performance physical. exercises and other types of D. causes specific and nonspecific psikhofiziol. reactions. Specific psikhofiziol, reactions are characterized by improvement of function, stability and reliability of all fiziol, systems in exercises, this look, and also at exhaustion, etc. At the same time improvement of an organism in the course of it can be reached ontogenesis (see), and also optimization of balance of an expense and recovery of biopower and structural reserves at the movements of various intensity and under different conditions.

Nonspecific psikhofiziol, reactions provide increase in stability of a human body and an animal to action of adverse factors (ionizing radiation, toxicants, a hyperthermia, a hypoxia, infections, various patol, processes, etc.). A physical activity promotes adaptation of a human body to changes of the environment (climate, time zones, conditions of production etc.).

Different types of D. are characterized by dynamics of physiological processes which by their optimization provides the best preservation of life activity of an organism. The excessive mobilization of functional activity which is not provided with the necessary level of coordination and activity of recovery processes during work and for a long time after its termination is characterized as a giperdinamiya. This state arises at excessive sports or heavy physical. work, at long emotional stresses, etc. Giperdinamiya develops as a result of mobilization of functions, inadequate for a functional condition of an organism, neuromuscular, cardiovascular, respiratory and other systems and can be followed by a number of painful symptoms.

Other pole of a physical activity is hypodynamia (see). This state is characterized by decrease in activity of all bodies, systems and disorder of their interrelations in an organism. Various parties of a metabolism are exposed to profound changes, reliability and stability of a human body and an animal at considerable functional loads and action of adverse environmental factors decreases.

In general the available data allow to speak about a physical activity of the person as the process in many respects promoting preservation of his health and labor activity. Achievement physical. perfection — an important result of all variety and interrelation of various movements on character at all levels psikhofiziol, regulation of a complete organism.

Biomechanical bases of the movement

Main objectives of a research biomechanics D.: nature and nature of the organization of power interactions of different parts of motive systems with each other and environment; coordination schemes and principles of creation of D.; power of motive acts.

Functionally the simplest are the postural D. providing maintenance of a pose and the motionless provision of an organism in space and also the locomotory D. providing space movement of an organism.

Unlike technical designs and constructions which stability is usually passive and statically a ravnovesna, poses of animals and the person, behind the few exception are active and dynamically equilibrium. Different poses can be classified by number of points of support to which there can be 0, 1, 2, 3... item. Poses (k-pose) at k≥3 are called statically steady if the center of gravity of an organism is in a projection to the plane of a support in a basic polygon or a triangle (at k = 3). The pose of vertical standing of the person can be considered as a pose, stability the cut from the mechanical point of view is solved an organism at the same time in two ways: due to the background activity of muscles providing necessary rigidity of joints (the pose is steady against small indignations), and due to the adjusting activity of muscles of a body minimizing deviations of the center of gravity from position of balance. Vertical and other active poses of the person (e.g., deduction of a load the taken-away extremity) are followed by low-amplitude accidental fluctuations, or the postural micromovements caused by pulse pattern of activity of muscles and mismatches of regulation. Registration and the analysis of postural micromovements make a basis of a wedge, tests of disorder of motive functions of the person.

At a large number of basic extremities — four-footed vertebrata, insects, etc. — poses of standing are statically steady and for their maintenance to provide necessary elastic rigidity of extremities enough.

The principle of ensuring static stability is taken for the philosophy of the analysis of walking of quadrupeds, edges is considered at the same time as continuous change of statically steady poses.

Different forms of locomotions of organisms are defined by properties physical. Wednesdays, due to interaction about a cut space movement, and features of the organization of motive systems is carried out.

There are three forms of locomotions: water — the swimming which is carried out due to the rowing movements of fins or extremities, undulations of a body or by means of reactive propellers; overland (crawling, walking, run and jumps) — also the air locomotion (weeds) which is carried out by means of wings is carried out by means of extremities.

Movements of single cells (amoebas or fibroblasts) are carried out by consecutive local attachments to substrate and the subsequent otkrepleniye — the so-called amoeboid movement. Dynamics such locomotions can be defined briefly as rhythmic pullings up to new places of an attachment. In this way also some marine benthonic animals interact with substrate (stars, hedgehogs, holothurias, etc.). During the walking and D.'s run are created due to pushing away from soil. During the swimming (due to the rowing movements of fins or extremities) or flight (by means of the waving wings) motive powers are repellent; slipping of propellers concerning Wednesday is characteristic of these locomotions and the size of motive power is proportional to the speed of the movement of the propeller concerning Wednesday. For rowing (during the swimming) and swing (during the flight) D. is essential the special organization of the movement in different phases of a cycle: the movements in an active phase create the maximum motive power, and in a phase of return render the minimum counteraction. In different organisms problems of the optimum organization of movements are differently solved.

Except postural and locomotory, there is a big class of any special movements (behavioural, labor, sports, dancing and so forth) which biomechanical characteristics because of complex and various structure of their organization it is difficult to characterize in a habit view.

Motive systems

At metaphytes the motive system forms from a skeleton and muscles.

The skeleton performs basic function of creation of D., is a basis of fastening of muscles, defines the possible directions of movements of a body or extremities. The connected consistently mobile links of a skeleton form kinematic chains of extremities and a body of animals and the person. As mechanical measure of mobility of a kinematic chain serves the number of degrees of freedom, i.e. number of explanatory variables (number n), possible D., necessary for a complete description, of a chain (e.g., the uniaxial joint has one degree of freedom — D. are described by one variable — a joint corner; biaxial and spherical joints have two degrees of freedom — D. in them are described by two corners). The number of degrees of freedom of a kinematic chain is equal to the sum of degrees of freedom of all joints of this chain. Similarly the number of degrees of freedom of motive system is defined. Completely to describe D. of system with p degrees of freedom (n-system), it is necessary to determine the generalized coordinates of this system q1, q2..., qn as function of time (t), i.e. q1 = qi (t), where i = 1, 2..., to n-number of degrees of freedom. This set is considered as a vector of q = (q1..., qn), t. e. as a point of n-dimensional space of configurations of Q = {g}, and the movement of n-system — as a trajectory of this point in space of Q. In specific motive objectives dimension of Q is defined by number of the considered degrees of freedom of the considered system. E.g., the space of configurations of shagatelny movements of a leg of the person in case of rectilinear walking can be represented, without a center of gravity position as four-dimensional: Q = { q1, q2, q3, q4 } where q1, q2 etc. represent corners — coxofemoral, knee, talocrural and feet with a support; for D. squats without separation of a heel of Q can be represented as three-dimensional.

Postural tasks in itself are complex tasks since in addition to correction on a mismatch it is necessary to create background elastic rigidity of the kinematic purposes here. For locomotory movements the background is made by the motive program of implementation of certain functional states (a problem of consecutive change of poses of an organism). Besides, owing to different accidental hindrances and mismatches the corrections providing the accuracy of implementation of the program are necessary. Ideas of the hierarchical organization of movements of an organism and ways of management with participation of different levels of c. N of page make a basis of the concept of N. A. Bernstein about the principles of creation of movements. The main division of managing functions is carried out in c. N of page (see. Motor analyzer ). Except the specialized muscle and tendinous receptors participating in regulation of movements, cross-striped muscles are heterogeneous on mechanical characteristics of the fibers making them — along with more bystry fibers there are slower here that is necessary for the solution of different motive tasks (from bystry change of phases of the movement before creation of constant tension of a tone — at deduction of a load or maintenance of a pose).

As power sources muscle fibers are asymmetric, or unidirectional; the active forces in points of an attachment of fiber arising at reduction of sarcomeres are oriented along fiber in the direction of reduction, i.e. fiber is only capable to reduce the length and distance between points of an attachment, but is not capable to increase in length. Therefore motive systems of organisms will usually be organized by the principle of pair antagonistic muscles (flexor muscles and extensor muscles).

Originality of tasks of the organization D. of organisms — in redundancy of degrees of freedom of their motive systems, thanking to - the swarm is reached a big variety of forms D. and forms of motive behavior. On the other hand, each specific D. — result of a reduction of excess degrees of freedom which is achieved by the coordinated activity of many muscles. Further development of this look — definition of «language» of creation of D. on the basis of a concept of synergy, i.e. joint participation of different muscular groups in the movement, or steady motive stereotypes (or inborn, acquired in the course of training). Just as synergies of pronouncing words represent different complexes of «elementary» synergies of pronouncing letters and syllables, and pronouncing phrases forms from synergies words, and the general problem of creation of D. of organisms can be considered as a problem of hierarchical synthesis of difficult motive acts on the basis of simpler. Thus, the question of the analysis of any D. comes down to definition of «dictionary» of D. in the form of a set of elementary synergies and ways of formation of difficult synergies from elementary.

In full statement the research problem of synergies is extremely difficult. In practice are usually limited to the analysis of a small number of bonds between the main characteristics of D., i.e. consider not all real degrees of freedom of motive system but only a nek-swarm their subset characteristic of the studied D. Shagatelnye D. of extremities can be described functions of joint corners, but are often limited to simpler scheme — a research of rhythmic structure of shagatelny. The rhythmic scheme is not only the simplest, but also the most universal since on its basis it is possible to compare not only different forms of locomotions, but also in general different rhythmic. The main question of the choice of this or that scheme of the description of D. — definition of a full set (M) of the independent parameters characterizing this movement within the chosen scheme. Then the M can be represented as «motive space».

In the rhythmic scheme of the description of shagatelny D. all extremity is considered as some «pendulum» which is making fluctuations with the period of T, but having different phases T of duration - — support, T+ — transfer. Fluctuation band is defined by either the angle of swing, or length of a step of l = vT where v — the speed of walking. All these parameters change with change of speed. Locomotory rhythmics of a single extremity completely is defined by three parameters, e.g. T, T+, l which can be accepted for independent, and to find the others from definienses: T-= T — T+, v = l/T, v + = v/γ, where v + — the average speed of a distal point of a leg in a phase of transfer, a γ = T+ T - — the parameter of structure of a cycle. A set of M = { T, T+, l } — the elementary Motive three-dimensional space. If similarly to build motive space of walking of the person, then generally it is necessary to consider six-measured space. However normal at people rhythmics of both legs will usually be organized equally, and cycles of legs always of a protivofazna, and the initial six-measured space is reduced in three-dimensional space. Definition of dependences between parameters of space of M in the different modes of walking of the person is equivalent to identification of species of additional kinematic synergies of one extremity. Except normal natural walking with different speeds, for this task it is enough to study still «the isorhythmic modes» — walking with different speeds of v at the fixed values of a rhythm (T = const), and also «the isometric modes» — at the fixed values of length of a step (l = const). In each mode of walking kinematic parameters are different unambiguous functions of speed of v, but are connected a nek-swarm of the general for all modes by functional dependence:

F (T, T+, l) = 0. (1)

Geometrically it means that in three-dimensional space of M allocate a two-dimensional subspace, Krom possesses all modes of walking, i.e. the equation (1) defines the general for all modes kinematic synergy of walking. The special modes unambiguously are defined in M by additional (artificial) synergies of type:

T = const, l = const, (2)

t. e. one of conditions (2) together with (1) allocate a one-dimensional subspace in M. For normal walking a role of a condition (2) is played by constancy of the work of time of transfer at length of a step (T of +l = const).

The power principles of the organization of movements

At D.'s descriptions the main are concepts of a motive energy proportional to a square of speed of D., and a potential energy proportional to height of a body over the Earth's surface (at vertical movements in gravitational field of Earth), or to a square of shifts from position of static balance (at elastic deformations). Besides, D. of all real systems are connected with overcoming external and internal friction forces and loss of mechanical energy — its transition to heat energy. Chemical energy of metabolic processes is a source of motive powers of organisms (see. Muscular contraction ). Measure of change of energy is work of forces which are carrying out D. — forces of inertia in case of a motive energy or forces of gravitation and elasticity in case of a potential energy.

Locomotory and many other movements of organisms are significantly active, i.e. are connected with constant power consumption of muscles on formation of motive and managing powers, but may contain separate phases of the passive movement on inertia. For active D. a role of a power analog of motive synergies is played by a minimum of the spent work. This approach is even more often used for the analysis of dynamics of walking, swimming etc. The theoretical analysis of mechanical models shows that the condition of minimization of work imposes restrictions for the organization of motive acts and the predictions for a kinematic picture D. which are turning out at the same time will be coordinated with real. The principle of a power optimality forms a physical basis of formation of motive synergies and (perhaps) is the leading principle of training in different movement skills. Of course, this principle is not the only factor of the organization of the movement, and the live organism solves a problem of motive behavior proceeding from many different requirements, but among a set of possible solutions of each motive task the options optimized energetically are chosen. E.g., tactics of the organization of sprint and stayer locomotions is various, but as motive cycles have the complex organization, in each of these cases there are optimum local tactics of creation of D. of separate links of kinematic chains. Depending on the general problems of a condition of optimum distribution of energy costs can change, i.e. criteria for evaluation of an optimality of D. Odnako irrespective of criteria can change the requirement of an optimality is equivalent to the requirement of an optimality at all levels and subtotals of the organization D. Therefore the requirement of a global power optimality extends to all links of motive system, i.e. unambiguously defines all picture of the dynamic and kinematic organization D.

The system principle in the organization of movements. In classical physiology of D. consider as function of muscular tissue or the musculoskeletal motive device of the person or an animal what is expression of the general aspiration to differentiate its structure and function in each object of a research.

Fiziol, the analysis of the nature of D. (both mechanisms of their emergence, and ways of their implementation) long time was based on the reflex theory.

Followed it morfofiziol. researches made possible to use D.'s analysis not only for profound studying of the mechanism of nervous control of D., but also in practice a wedge, diagnoses of diseases of a nervous system.

In a research D. approach which developed in differs in a certain originality ethology (see). Observing natural difficult behavior of animals, ethology tried to spread out it to simple components, to allocate a number of categories of behavioural acts (ritual acts, defense reactions, etc.), however unlike physiologists they did not move to a level of the analysis of separate muscular contractions. As it appeared, instinctive D. of animals are very stable and can be used for the classification purposes.

Craig (W. Craig, 1908) subdivides the instinctive movement into preparatory behavior and behavior of the completing act.

On development of the doctrine about difficult motive acts huge impact was exerted by researches a wedge. - nevrol. the frustration arising at various forms of pathology of a nervous system.

Is later a theoretical basis of understanding fiziol, the mechanisms which are the cornerstone of purposeful behavior there was a theory of functional systems of P. K. Anokhin. From positions of this theory of D. are considered as a stage of the behavioural act, the purpose to-rogo is obtaining useful adaptive effect, and out of the behavioural act of D. loses the biol, specifics. The theory of functional system considers management process of D. only within the motive behavioural act as only the behavioural act provides useful adaptive effect and has necessary completeness of the properties inherent in a complete object. Management process of D. from these positions turns from process of formation of the sequence and line-up into process of the organization of specific system, in living conditions a cut this flow of actions will be a necessary and natural stage of its existence.

Process of formation of the motive act is defined by at least three factors: it shall be directed to satisfaction of the requirement (motivation) conducting at present; the result of this motive act shall correspond planned and created in the form of its model in acceptor of results of action (see); the motive act is characterized by structure and the sequence of the actions necessary for obtaining result.

If analytical approach satisfied with the ascertaining of existence of simple components within the difficult complete phenomenon, systems approach is faced by a problem of clarification of the mechanism of association of parts in more difficult whole (see. Systems analysis ). Already the first steps in development of methods of partitioning of complex systems resulted in understanding of need to refuse as from purely morfol., and from purely functional criterion at its implementation as within systems approach concepts of structure and function lose the former absolute value.

From modern positions the partitioning which is carried out according to the hierarchical organization of an object shall be the most adequate partitioning of a system object on its components.

Paying attention to importance of a problem of hierarchy, P. K. Anokhin (1973) wrote: «... we never have really isolated functional systems of the organization, it is possible only with the didactic purpose to choose the certain system providing useful result at this level of hierarchy of systems... It is not difficult to understand that, having opened real physiological mechanisms of association of functional systems of various levels, we would approach a solution of the problem of organic combination of the analysis and synthesis in the most research process. At formation of hierarchy of systems any more low level of systems shall organize somehow contact of results, as can make the following more high level of systems».

The accounting of hierarchical structure is especially necessary in the analysis of complete motive acts of the person since the local motive act' becomes possible and justified in its adaptive sense only in interaction with postural activity.

In any complete motive act it is necessary to consider specifics of relationship in the sequence of motive acts as the behavior in general represents continuous function, so-called true continuum of results. Speaking about such continuum of results, it is necessary to emphasize that in any purposeful behavior accurately select the completing act most of which brightly expresses the purpose of behavior and group of preparatory acts which create conditions for achievement of goals.

The big contribution to studying of the mechanism of management of motive systems was made by N. A. Bernstein's researches. It showed that management of motive systems of the signals coming only from the motor area of a cerebral cortex is essentially impossible. The motive act is always «multi-level» education where each level contributes the share in implementation of «a motive task».

Pathology of movements

Patol, D.'s changes which are found in clinic are diverse. They can concern disturbances of rate of D., their character, coordination, is more often — restrictions of volume and D.'s force (see. Paralyses, paresis ), violent excess D.' presence (see. Hyperkinesias ) or delays and D.'s restrictions (see. Bradykinesia ). Defeat of a peripheral link of a motor analyzer leads to a flaccid paralysis: both any and reflex D. drop out, the atony and an atrophy of muscles, changes of electroexcitability develops. Otherwise defeats of pyramidal system are shown: deep reflexes do not die away, and raise, the spastic muscular hypertension develops, there are so-called pathological reflexes (see. Reflexes pathological ).

The akinesia

the Term «akinesia» is used for designation of various manifestations of an obezdvizhennost in the motive sphere at the person and animals. Less expressed degrees of an obezdvizhennost are designated as hypokinesia (see). In medical practice akineziy call the states which are shown decrease loudspeakers D. in general, the general falling of level of motor functions and a motive initiative.

The picture of an akinesia is most typical at an akinetiko-rigid form parkinsonism (see). In such cases of the patient not movably lies or sits in a bed, his motility is extremely limited, he tests a condition of the general constraint, any D. are slowed down, inclined to hardening; the person is expressionless, maskoobrazno. The motive delay changes handwriting of the patient; he writes with slowly small handwriting (micrography).

In an origin of an akineziya, apparently, a peculiar increase in a tone of muscles of a body and extremities and development in them of rigidity, i.e. a plastic hypertension matters. It differs from pyramidal spasticity in what arises and keeps in all phases of a muscle strain.

The akinesia develops at defeats of the underlying structures of a brain (black substance, a reticular formation of a brainstem, a pale sphere, frontal and subcrustal bonds) controlling the Extrapyramidal physical activity and a muscle tone. Elektrofiziol, researches indicate considerable lengthening of time of carrying out vozbuzhdeniye from a cerebral cortex on segmented devices of a spinal cord.

It is established that low level of functional activity of deep areas of a brain at an akinesia is caused not only by organic changes in these structures, but also disturbance in them biochemical, processes. There is a parallelism between expressiveness of an akinesia and falling of concentration of dopamine in striatal educations and black substance of a trunk of a brain. Deficit of dopamine reduces activity of dofaminergichesky neurons in subcrustal nodes and leads to «dissonance» of motive programs.

At patients with an akinesia under the influence of various stressful states motive crises which are collectively called «a paradoxical kinesia» can take place; the immobilized patient rastormazhivatsya, becomes active, is capable to make D., difficult on creation (run, walking, games and so forth), however then again falls into a condition of an akinesia. Attacks of a paradoxical kinesia should be considered as periodic activation of cortical motor zones with suppression of a pathological dominant.

The special form of a disease is represented by a so-called akinetic mutism. It can come at defeat of oral departments of a brainstem and reticular formation, limbikoretikulyarny complex; proceeds subacutely or chronically. The patient in a condition of an akinetic mutism in a phase of block, lies in a bed not movably, does not execute the command, emotions are absent, the speech shepotny, hardly audible. The small movements of eyes are sometimes noted. On EEG the considerable depression of an alpha rhythm is observed. The condition of global braking is interrupted sometimes by convulsive crises and hyperkinesias (see. Myoclonias , the Torsion dystonia etc.).

The lethal outcome at these states can be caused by disturbance of vital functions and development of respiratory and cardiovascular insufficiency.

The condition of an obezdvizhennost can accompany also other diseases of a nervous system, napr, at patients with neurosises as a result of fixing of painful states and persistence in the motive sphere, phobias etc. Hysterical manifestations of an obezdvizhennost carry the name of «a symptom of imaginary death» by analogy with hardening of animals in response to a situation, life-threatening. Considerable braking of motor reactions quite often supplements a picture of psychosis (schizophrenia, maniac-depressive psychosis, a neurosis tarda).

Akineziya can develop as result of intoxication of subcrustal nodes at prolonged use of neuroleptics (aminazine, Reserpinum, Stelazinum, etc.) — a so-called akinetic form of aminazine parkinsonism, rezerpinovy parkinsonism, etc.

Akinesia algera — painful immovability. The movements are absent because of considerable morbidity though noticeable signs of organic lesion are not found; it can be connected with diffusion muscular diseases (e.g., a miositis, a dermatomyositis, etc.). Patients with months do not leave a bed. All cases of an akineziya of such form demand careful a wedge. - fiziol, the analysis.

Lacks of coordination of movements

D.'s Coordination normal at the person is carried out at all levels of c. N of page — a spinal cord, a mesencephalon, a labyrinth, a cerebellum, a thalamus, frontal department of hemicerebrums.

Fig. 1. Disturbance of the combined movements (a mismatch of work of synergistic muscles) at a rising at the patient with a cerebellar asynergia: in attempt to sit down without hands legs rise (in the drawing on the right; at the left — physiological synergy).
Fig. 2. Disturbance of the combined movements at the patient with a cerebellar asynergia: 1 — during the walking the movement of a trunk lags behind movements of legs; 2 — at an inclination consensual bending of legs lags behind in knee joints back that leads to falling of the patient (in the drawing at the left — physiological synergy at an inclination back).

In clinic usually understand such conditions of a physical activity which are characterized by a mismatch of muscle work — synergists (fig. 1), agonists and antagonists, disturbance of dynamic stabilization of D. and their untimely performance as disorders of coordination of D.

The leading symptoms of a lack of coordination of D. (diskoordination) are the ataxy, a dyssynergia, a dismetriya (see. Ataxy , Cerebellum ).

Disorders of coordination of D. are caused by various organic processes in c. N of page: tumors, abscesses, encephalitis, arachnoidites, demyelination, hemorrhages, ishemiya, degeneration, etc. Damages of cerebellar structures lead to disturbance of basic reflexes, decrease in a muscle tone and emergence of a static ataxy. The patient goes, widely placing legs, is unsteady during the walking here and there («gait drunk»), balances as the person going on a rope. During walking the picture of an asynergia (fig. 2) is noted — there is no normal combined bending of legs in coxofemoral, knee and talocrural joints, legs move ahead of a trunk — a truncal ataxy, etc. Maintenance of a vertical pose of the patient because of difficulty of deduction of balance is impossible, there is a bent to fluctuations of a trunk and falling — a so-called symptom of Romberg (see Romberg a symptom).

Fig. 3. Disturbance of movements of a hand at the patient with a cerebellar asynergia: at the movement of an index finger from a nose of the patient to a finger of the researcher there is an intentsionny trembling (the trajectory of the movement is specified by a dashed line).

Disturbances of functions of hemispheres of a cerebellum involve emergence of a dynamic diskoordination: each D. of the patient becomes uncoordinated, stirred up, wide. The dynamic ataxy is shown on the party of damage of a cerebellum. The patient cannot outline a hand space in the form of a circle (there is a broken, zigzag line). At calcaneal and knee test a leg, being in steps shaken, touches not a knee, but a shin of other leg. The index finger did not possible to get precisely to a tip of a nose, D. become disproportionate, there are swings, boldness, intentsionny trembling joins (paltsenosovy test — fig. 3).

Lack of stability at D. influences handwriting of the patient: the line becomes disproportionate, letters uneven, big.

As a result of close connection of a cerebellum with bark (frontal mosto - a cerebellar way and other ways) in some cases the tendency to regress of cerebellar frustration due to cortical functions appears. A static and dynamic ataxy quite often appear at defeat of a brain trunk where a number of the centers responsible for a postural tone and D.'s coordination is located (the lower olive, a reticular formation, cerebellar legs other). Such disturbances with existence of a hypomyotonia are most expressed at the centers in lateral departments of the bridge and a myelencephalon. Participation of a red kernel, an upper leg of a cerebellum is shown by trembling, a taksiya, strengthening of postural reflexes and placing reactions on the party opposite to the center of defeat. At cortical disturbances of disorder of coordination come also on the heterolateral party. Lacks of coordination are most considerable at patol, the processes affecting frontal and temporal departments of a brain. The phenomena of a diskoordination of D. accompany spinal processes and come when the afferentation from proprioceptors of muscles and joints to a cerebellum on back cords is broken. Gait of the patient becomes uncertain and shaky. Hypotonia of muscles leads to overextension of joints. At switching off of visual control (in the dark and at the closed eyes) the ataxy sharply increases (tabes, Fridreykh's disease).

Mechanisms deafferentation (see) are the cornerstone of an ataxy at multiple defeat of peripheral nerves — polyradiculoneurites (see. Polyneuritis ), at which carrying out sensitive signals in a cerebellum is blocked. The tone of muscles decreases, gait and D. become uncertain and shaky (peripheral tabes, alcoholic pseudo-tabes). Such ataxy is followed by signs of neuromuscular defeat —


At the healthy person mechanisms of coordination provide with pains, disorders of sensitivity, decrease in proprioceptive reflexes etc. performance of the opposite following one after another. This normal function is connected with a reciprocal innervation, edges prepares change of phase reactions in system agonists — antagonists.

At damage of a cerebellum (tumors, multiple sclerosis, dystrophic processes, hemorrhages, etc.) at the patient there comes the impossibility of carrying out at bystry speed rhythmical, opposite on a sign D. — so-called adiadokhokinez (a kind of a cerebellar asynergia). Adiadokhokinez is found by means of various a wedge, tests which cornerstone change at bystry rate of simple is. In particular, the patient at the request of the doctor makes bystry (or with increase in speed) pronation and supination of brushes (synchronously). At an adiadokhokineza such D.' change is complicated, slowed down, broken D.'s rhythm, their disproportion is noted. Adiadokhokinez is found on the party of damage of a cerebellum. Existence of damage of a cerebellum confirms also a combination of an adiadokhokinez to other symptoms of a cerebellar diskoordination.

Grotesque manifestations of lacks of coordination in a certain combination — disorders of standing and walking with full safety of other systems and functions (see. Astasia abasia ) — are treated in clinic as displays of motive neurosis (hysteria).

The movements at advanced and senile age. D. Nablyudayutsya's changes delay of speed, disturbance of rhythm and accuracy, reduction of amplitude and D. Narastayet's plasticity muscle tension are characteristic of the elderly and old person, there is an easy tremor of hands and the head (see. Trembling ), the possibility of simultaneous performance of several D. is limited, thin D.' performance is at a loss, handwriting changes. The mechanism of these shifts is in many respects connected with insufficiency of extrapyramidal system.

Data of EMG (growth of coefficients of a retsiproknost and adequacy, indistinct separation of «packs» of biocurrents from bestokovy sites, changes of EM G of rest) confirm changes of the central mechanisms of coordination of D.

Age changes of static and dynamic coordination of movements

Age changes of static and dynamic coordination of D. have the difficult mechanism and can be understood at the accounting of the functional and structural shifts coming in cortical department of a motor analyzer, a cerebellum, subcrustal and trunk educations. Peripheral mechanisms also participate in disturbance of locomotory coordination. Age changes of the muscular and copular and joint device lead not only to D.'s restriction, but also to weakening of the tendon jerks which are important stage of latency of tendon jerks in connection with increase in the central time of a reflex and delay of carrying out excitement on motor nerves and neuromuscular synapses increases in formation of plasticity of D. K of an old age.

At advanced and senile age formation of new movement skills is at a loss, the structure of ergografichesky curve any muscle performance changes (see. Ergografiya ), what is defined by disturbance of dynamics of nervous processes — weakening of process of braking and inertness of exciting process.

Bibliography: Alexander R. Biomekhanika, the lane with English, M., 1970, bibliogr.; Anokhin P. K. Internal inhibition as problem of physiology, M., 1958; it, Biology and neurophysiology of a conditioned reflex, M., 1968, bibliogr.; Arshavsky I. A. Physiological mechanisms of some main patterns of ontogenesis, Usp. fiziol, sciences, t. 2, No. 4, page 100, 1971, bibliogr.; Bernstein N. A. About creation of movements, M., 1947; about N e, Sketches on physiology of movements and physiology of activity, M., 1966, bibliogr.; Granite P. Bases of regulation of movements, the lane with English, M., 1973, bibliogr.; L at r and I am A. R. the Highest nervous functions of the person, M., 1969; The Principles of the system organizations of functions, under the editorship of P. K. Anokhin, page 5, M., 1973; Development of sokratitelny function of muscles of the motive device, under the editorship of L. G. Ma-gazanika and G. A. Nasledov, L., 1974; Physiological problems of a detrenirovannost, under the editorship of A. V. Korobkov, M., 1970; Physiology of movements, under the editorship of V. S. Gurfinkel, L., 1975; X and y N d R. Povedeniye of animals, the lane with English, M., 1975; Sh about in e of N of R. Povedeniye of animals, lane with fr., M., 1972.

Pathology — Vartenberg R. Diagnostic tests in neurology, the lane with English, M., 1961; M and l of N of e r Item. Physiological psychology, the lane with English, M., 1973; The Multivolume guide to neurology, under the editorship of G. N. Davidenkova, t. 2, page 110, M., 1962; Petelin L. S. Extrapyramidal hyperkinesias, M., 1970; Fudel-Osipova S. I. Aging of neuromuscular system, Kiev, 1968, bibliogr.

A. V. Korobkov; L. S. Petelin (not BP.), V. A. Polyantsev (systems analysis), V. V. Smolyaninov (biomechanical bases of D.), S. A. Tanin (geront.).