K.D. Chermit, professor, Dr.Hab., Dr.Biol.
A.V. Shakhanova, professor, Dr.Biol.
A.G. Zabolotniy, associate professor, Ph.D.
Adyghe State University, Maikop

Keywords: harmonic pair "symmetry/asymmetry", manual asymmetry, lateral dominant, dextrastress, laterality accounting principle, sports training.

Introduction. The methodological base of the presented concept is the principle of self-organization of the body and the system symmetry method for studying complex phenomena. The principle of self-regulation is a major condition of self-organization.

The essence of the principle is that deviation of any result of operation of the functional systems from the level determining the normal vital activity of the body causes mobilization of all components of the system and strengthens their interaction. The entire functional system operates to recover the altered state to the level determining the optimal course of the vital processes.

Moreover, even with the internal factors being the leading ones, a conflict between the system and the environment is the dominant of self-development and self-organization of the system [7]. Development can be provided by way of either structural or functional reorganization.

The purpose of the study was to give a scientific explanation of the terminology of sports lateral stress.

The structural criteria consist in understanding of the process of development as a series of qualitative changes in the structures of the material system, are expressed in irreversible changes and aim for both structural simplicity and structural complexity, for which reason the phenomenon is reflective of the dialectical law of negation, and the law of negation is seen in case of the mutual effect of symmetry-asymmetry, which, while estimating the body state defined as harmonious, helps move from empirical contemplation to its designing using values and patterns.

Proceeding from the previous studies of the display of symmetry in the human body two important points of the current scientific work can be stated:

1. The components of the body state, defined as harmonious, are an appropriate display of symmetry and its quality reproduction with particular rhythm, while retaining the vector of development. Symmetry and rhythm act as essential forms of expression of the time-space unity of the body's subsystems. Their interaction is an essential condition for resolution of the conflict between old and new states. The objective laws of symmetry and rhythm show themselves in the structure, functioning and development of the systems, and thus reflect the common laws of nature.

2. Such category as "symmetry", when accompanied by its opposite - "asymmetry", with the need for the formation of the harmonic pair "symmetry/asymmetry", implied and completed by the latter, makes it possible to study the cause-effect relationships of the body's tolerance and changeability, which ensures human ontogenesis.

Being the universal principle of development and functioning of nature, the harmonic pair "symmetry/asymmetry" explains a number of biological mechanisms of adaptation and development of the human body.

An open system, as is the human body, when assuming an unlimited range of amplitude variations, contributes to the left, right and symmetric reactions. The focus and force of the impact determine the level of adaptation, physiological regulation of an individual's development and improvement. They depend on the influence of:

• constant factors;
• gradually rhythmically or aperiodically recurring constant external factors;
• rhythmically or aperiodically recurring relatively constant external factors;
•  consistent range of never recurring factors.

Each of these factors affects to some extent the symmetry/asymmetry of physical development and development of movements, and thus requires an in-depth study.

It is the first two factors that are topical in this scientific work, so let us bring them into focus.

Among the constant factors, exercising a remarkable influence on the formation of left- or right-handedness, genotype is single out by scholars. It is evidenced by the data received by E.G. Semiritskaya (1985), I.V. Ravich-Shcherbo (1988) et al, which indicate that left-handedness is more common for families where at least one of the parents is a lefthander [5, 6].

The data obtained during the in-house studies testifies to the genotypic theory of formation of the functional asymmetry, but with certain reservations.

The relationship between laterality of the cerebral cortex activities and asymmetries in motor actions stipulates the formation of the random use of either right or left side of the body at the same period. Gradual transition from unsteady symmetry to unsteady asymmetry of functioning of the locomotor system is observed at the second half of infancy (observation of infants (n=32), we determined how often right or left hands were used during pincer prehension and manipulative actions).

Results and discussion. The obtained data suggest that right- and left-handedness are defined, most probably, by genetic preconditions. Herewith, progressive changes in physical development at the early stage of ontogenesis, irrespective of which means are used to achieve them, result in the increase of lateral dominance of the response hand (swimming). In other words, the effect of environment (including parents) on the formation of right- or left-handedness can be just a limiting or a precipitating factor, but no way a determining one.

In addition, special attention should be paid to the fact that this conclusion is fair only regarding infancy.

The obtained data on older children testify to the dominant effect of environment on the formation of the level of manual asymmetry. Thus, by the time of entering school the number of the frankly left-handed amounts to 20%, and of the frankly right-handed - to 53.33%. By the age of 6 5% of left-handed children switch to the group of ambidexters, and around 30% of ambidexters become right-handers.

The number of individuals who prefer using right hand when performing monolateral movements increases with age and reaches 90% at the age of 13. No left-handers were found among high-school children, and the number of ambidexters amounted to 10%. That is, "pressure of the right-handed culture" is obvious.

The detected relationships between the indicators of motor asymmetry and their externally influenced dynamics depending on the initial level of asymmetry enables us to notionally single out 5 groups of children: 1 – frankly right-handed; 2 – ambidexters prone to right-handedness; 3 – ambidexters; 4 – ambidexters prone to left-handedness; 5 – left-handed.

Living and educational environment, usually, influence the formation of right-handedness. Each group responds to this kind of impact in its own way. The affirmative influence of the "right-handed culture" strengthens the dominance of the right hand in the right-handed, ambidexters and ambidexters prone to right-handedness. Ambidexters prone to left-handedness approach that level, where Ac coefficient is equal to 0, and often change the sign to plus, i.e. become ambidexters prone to right-handedness.

As seen from the adduced data, any kind of pressure on the frankly left-handed and ambidexters prone to left-handedness, prior use of their right hands when performing labor and any motor action does not seem appropriate. It is not only ineffective in terms of training, but, as evidenced by the study, also adversely affects children's health [1, 4, 7].

Based on the findings, it can be concluded that in the psychomotor development of a school-age child an inherited predisposition to right-handedness or left-handedness is firmly fixed in a particular position, though there are some shifts caused by environmental effects. It should be understood that among the factors, contributing to the shift towards imprinting of right-handedness, standards of training in writing skills, drawing skills, exercises and other factors of educational and professional activity hold a specific place. The latter judgment is based on the data received during examination of people of different professions.

Therefore, three key factors interact during asymmetry formation, which are as follows:

• genetic predisposition to prior use of one side of the body;
• environmental influence, the focus of which is determined by the right-handed society, which, in turn, forms writing and drawing standards;
• usage of particular side of the body when performing cyclic actions, which lead to the formation of ambidexterity due to their proportional use when moving.

In terms of organization of influence on the formation of "handedness", the stability of man's asymmetry in different age groups is also of some interest. In order to investigate these circumstances the same subjects were re-tested one week later. The established range of values х ± σ of the first-second testing clearly reveals the stabilization of asymmetry by the age of 10 (almost complete interpenetration of indices) both in boys and in girls.

The peculiarities of adaptation of the body of athletes to the impact also comply with the principles of interrelation of genetic inclinations and environmental effects, as evidenced by the results of the long-term in-house studies and examination of schoolchildren, outlined in theses on human physiology and sport didactics.

The significance of bilateral regulation when moving and during adaptation of the body to the impact of alien external environment [2, 4, 8] causes the development in the left-handed of the state, which is characterized by the term "dextrastress" (dexter – right, stress – pressure). As far as information goes, this term was first introduced into scientific use by A.P. Chuprakov in 1983 [3], when he described the states occurring in case of forcing left-handed children to write with their right hands.

As evidenced by the results of a large body of research in the sphere of sport didactics and vocational training, the phenomenon of dextrastress is also typical for other types of motor activity.

At the same time, based on the study of the common laws of development of man's functional asymmetry it can be said that dextrastress is observed only in the frankly left-handed, and less often - in ambidexters prone to left-handedness. It is difficult for these groups of people to perform complex motor actions to the right or with their right hand, which causes stress reaction.

Conclusion. The phenomenon of dextrastress in accordance with the dialectical laws of functioning of nature (the unity and conflict of opposites; symmetry as the basis for the organization of space, symmetry-asymmetry as a pair category of cognition of complex dynamic processes) should have its opposite manifestation in the form of laewisstress - left-hand stress. However, little attention is drawn to this factor in the educational system when determining the laws of construction of the system and process of sports training. In addition, the problem of dextrastress is specific even not for all left-handed athletes, but only for those with strong left-handedness. As for laewisstress, it affects the overwhelming majority of athletes, as influenced by the right-handed culture, ambidexters, ambidexters prone to right-handedness and even ambidexters prone to left-handedness acquire the right-hand dominant and the problems associated with insufficient skills in handling left-hand movements become vital for them.

The existence of dextrastress and laewisstress together provide the appearance of a generalized phenomenon, related lateral stress, and leads to the need to consider the manifestations of lateral stress as a principle of construction of the system and process of sports training.

References

1. Bezrukikh, M.M. Age features of organization and regulation of voluntary movements in children and adolescents / M.M. Bezrukikh, L.E. Lyubomirsky. - Moscow: Obrazovanie ot A do Ya, 2000. – 319 P. (In Russian)
2. Berdichevskaya, E.M. Hemispheric asymmetry profile and motor qualities / E.M. Berdichevskaya // Teoriya i praktika fizicheskoy kul'tury. – 1999. – № 9. – P. 21–26. (In Russian)
3. Bleicher, V.M. The explanatory dictionary of psychiatric terms / V.M. Bleicher, I.V. Kruk. – Internet resource http://vocabulary.ru/ictionary/28/word/dekstrastres. (In Russian)
4. Bragina, N.N. Human functional asymmetries / N.N. Bragina, T.A. Dobrokhotova. – Мoscow: Meditsina, 1988. – 366 P. (In Russian)
5. Ravitch-Shcherbo, I.V. The role of environment and heredity in formation of human personality / I.V. Ravitch-Shcherbo. – Мoscow: Pedagogika, 1988. – 159 P. (In Russian)
6. Semiritskaya, E.G. Human brain and mental processes in ontogenesis / E.G. Semiritskaya. – Leningrad: Publ. h-se of LSU, 1985. – 397 P. (In Russian)
7. Khomskaya, E.D. Neuropsychology of individual differences / E.D. Khomskaya (et al.). –Мoscow: Rossiyskoe pedagogicheskoe agentstvo, 1997. – 281 P. (In Russian)
8. Chermit, K.D. Symmetry, harmony, adaptation / K.D. Chermit, E.K. Aganyants. - Rostov-on-Don: Publ. h-se of NCSS HS, 2006. – 304 P. (In Russian)

Corresponding author: zabolotniy-tol1@yandex.ru