J.I. Busheva, associate professor, Ph.D.
O.G. Litovchenko, professor, Dr.Biol.
A.V. Auster, postgraduate student
Surgut State University of KhMAR-Yugra, Surgut

Keywords: morphofunctional indicators, motor activity.

Relevance. Man's residence in hypocomfortable climatic conditions combined with the anthropogenic load leads to more intensive use and depletion of adaptive reserves of the human body. Today there is scientific evidence of adaptive reactions in individual age-sex and constitutional groups of children of the North of Tyumen [5, 6]. However, so far there is not enough information on the evaluation of the morphofunctional status of the body of northern children born and living in the Middle Ob region [5] and engaged in physical culture and sport in the northern conditions [3, 4, 7].

The purpose of the research was to study the morphofunctional indicators of 9-year-olds from the North with various motor activity. 

Materials and methods. The study involved 120 pupils of the primary school № 2 in Surgut, KhMAR-Yugra. Children were divided into two groups: experimental group (EG) - 30 boys and 30 girls - 9 year olds, engaged in various sports (skiing, swimming, football, gymnastics, etc.) and attending school physical education classes (motor activity - at least 10 hours a week) and control group (CG) - 30 boys and 30 girls - children not doing sports, but attending physical education classes (motor activity - at least 3 hours a week). All children belonged to the same medical group regarding their health.

To estimate the multifunctional state of the body of 9-year-olds we applied a standard set of methods including: measurement of body length (BL), body weight (BW), chest circumference at rest (CC), heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, vital capacity (VC), Stange’s test, Genche’s test, calculation of stroke (SO) and cardiac (CO) output, birth-death ratio (BDR). Functional indicators (HR, SBP, DBP, SO, CO) were tested at rest and right after exercise (20 squats for 30 sec).

Results and discussion. Body length, body weight, chest circumference (total dimensions) are considered the most essential medico-social and sanitary-hygienic indicators, by which we can partially estimate both positive and negative effects of living conditions and environmental factors on the growing and developing organism [2]. Comparing anthropometric measurements of the examined 9-year-olds, we did not observe any differences in relation to their sex (Table 1).

Table 1. Anthropometric measurements of 9-year-olds from the North, М±σ

Note. Significance of differences at р<0,05: * – result differences between the girls from the EG and CG (within the indicator); ◊ – result differences between the boys from the EG and CG (within the indicator).

Thus, BL of the 9-year-old boys from the EG (128.6±5.2 cm) did not differ significantly from the corresponding indicator of the boys from the CG (130.1±5.4 cm). The girls from the EG were significantly shorter than their coevals from the CG (128.3±3.6 and 131.1±4.3 cm accordingly, at р<0,05). As for the BW indicator no significant differences were observed between the compared groups. CC of the male (65.4±3.8 cm) and female (64.9±4.2 cm) 9-year-olds from the EG was superior to their coevals from the CG (62.4±1.6 and 62.2±2.2 cm accordingly, at р<0,05).

HR is one of the most labile indicators of the blood circulatory system. The HR value depends on the age, sex and individual characteristics of a person. In 9-year-olds at rest it averaged to 82.3±10.7 – 89.0±11.9 bpm in the girls and 86.6±12.0 – 90.4±14.9 bpm in the boys (Table 2), moreover, the individual indicator values in all the examined groups varied heavily.

Table 2. Indicators of the cardiovascular system of the 9-year-olds from the North with various motor activity, М±σ

Note. Significance of differences at р<0,05: *, ** – result differences between the boys and girls from the EG (within the indicator); ○, ○○ –  result differences between the boys and girls from the CG (within the indicator); ◊, ◊◊ – result differences between the boys from the EG and CG; ▲, ▲▲ – result differences between the girls from the EG and CG (within the indicator).

There were no harsh sex-related differences in the experimental indicator of the 9-year-olds. Comparing the HR of the schoolchildren from the EG and CG, a more rapid pulse of the boys and girls from the CG can be noted.

The blood pressure (BP) value is one of the integrated indicators of functioning of the cardiovascular system. Whereas BP is a rather stable indicator, it may vary due to the changes in the functional state of the body [1]. The SBP level, registered at rest in the boys from the EG, was higher than that in the girls (at р<0,05). Increased SBP was observed in the children from the CG compared to the boys (р<0,05) and girls (р<0,05) from the EG. The post-exercise SBP values differed depending on sex only among the schoolchildren from the CG: the SBP level was higher in the boys rather than girls. According to the comparison of the blood pressure values of the children from the CG and EG, it was the boys from the CG whose SBP level was higher after exercise.

The DBP level at rest was higher in the children from the CG, with that, the sex-related differences were not found. Different DBP levels were also registered only in the schoolchildren from the CG: post-exercise DBP in the boys was higher than that in the girls (р<0,05). The level of this indicator was higher in the boys from the CG compared with their coevals from the EG, and a similar tendency was observed while analyzing DBP in the girls from the CG and EG.

Post-exercise CO in the boys from the CG was lower compared with that in the girls from the CG (р<0,05). In the children from the EG we observed a wider spread of the individual values of this indicator than in their coevals from the CG.

Stroke output (SO) refers to the basic hemodynamic parameters. It was higher in the boys from the EG rather than that in the girls (р<0,05). However, SO in the boys from the CG was higher than that in their coevals. The analysis of the CO values had not revealed any significant differences in respect to sex and the level of motor activity of the children, at a significant spread of the individual values of the indicator. SO, calculated based on the stress testing, increased to different extent. The most significant increase of SO after exercise was observed in the children from the EG (23 – 26 % of the initial level). The gain in SO in the schoolchildren from the CG was less significant - 3 – 14 %. The mean SV value in the girls from the CG was higher compared to the boys (р<0,05).

The respiratory system is one of the major ones and it determines the adaptive capacities of the body to a variety of environmental factors. In order to estimate the antihypoxic resistance of the body, we used the tests with breath holding during inhalation and exhalation - Stange’s test and Genche’s test. Assessment of the Stange’s test results (timed expiratory capacity), performed by the children (Table 3), revealed the lowered hypoxic resistance of the girls from the CG as compared to the ones from the EG (р<0,05). The average duration of the Stange’s test did not differ in the boys and girls from the EG, while the test results of the boys from the CG were better compared with the girls (р<0,05).

Table 3. Respiratory indicators of 9-year-olds from the North, M±σ

Note. Significance of differences: *, ** – result differences between the boys and girls from the EG (within the indicator); ○ – result differences between the boys and girls from the CG (within the indicator); ◊, ◊◊ – result differences between the boys from the EG and CG; ▲, ▲▲ – result differences between the girls from the EG and CG (within the indicator) 

According to the assessment of the Genche’s test results (timed expiratory capacity), the hypoxic resistance of the girls and boys from the CG decreased as compared to the children from the EG (р>0,05). The Genche’s test results of the boys and girls from the EG were better than those of the children from the CG. All the examined children had timed inspiratory capacity always more long lasting than the expiratory one.

VC is an integrated indicator which reflects the functional capacities of the external respiratory system in children and adolescents. VC depends on the pulmonary engorgement, state of diaphragm, level of muscular development and posture. Abnormalities of these indicators, changes in the pulmonary circuit result in the decrease of VC. The analysis of VC has not revealed any significant differences in the indicators of the schoolchildren from the CG and their coevals from the EG. The upward tendency of VC in the boys as compared to the girls was typical only for the children from the EG (р<0,05). The birth-death ratio (BDR) values, showing the volume of VC air per kg of a child's body weight, in the examined groups differed depending on their sex: the boys’ BDR values in both of the groups were higher than those of the girls (р<0,05).

Conclusion. The findings revealed the morphofunctional features of northern children at the age of 9 and can serve as criteria in the evaluation of the functional state of pupils doing sports in specific climatic and geographical conditions of the Middle Ob region.

References

1. Aghajanyan, N.A. Human ecological physiology / N.A. Aghajanyan, A.G. Marachev, G.A. Bobkov. – Мoscow: KRUK, 1998. – 416 P. (In Russian)
2. Baranov, A.A. Children's health in the Russian Federation / A.A. Baranov // Pediatriya. – 2012. – № 3. – P. 9 – 14. (In Russian)
3. Busheva, J.I. The study of physical development indices of 7-year-olds in conditions of sports occupations in the north / J.I. Busheva, A.V. Auster // Nauchny meditsinskiy vestnik Yugry. – 2012. – № 1 – 2. – P. 44 – 46. (In Russian)
4. Busheva, J.I. Morphological status of junior children involved in sport in the northern region / J.I. Busheva, O.G. Litovchenko, A.V. Auster // Teoriya i praktika fizicheskoy kultury. – 2014. – № 1. – P. 91 – 92. (In Russian)
5. Grebneva, N.N. Environmental portrait of modern children and adolescents in the Tyumen region / N.N. Grebneva. – Tyumen: Publ. h-se of TyumSU, 2006. – 240 P. (In Russian)
6. Koynosov, An.P. Age and constitutional peculiarities of children of the Middle Ob region / A.P. Koynosov, I.D. Kurenkova, A.E. Blinnikova // Nauchny meditsinskiy vestnik Yugry. – 2012. – № 1 – 2. – P. 133 – 136. (In Russian)
7. Litovchenko, O.G. Morphological and functional characteristics of primary schoolchildren of the northern city with different levels of motor activity / O.G. Litovchenko, J.I. Busheva // Fizicheskaya kultura: vospitanie, obrazovanie, trenirovka. – 2005. – № 6. – P. 21 – 23. (In Russian)

Corresponding author: apokin_vv@mail.ru