Abstract:

Introduction:
The lack of spontaneous physical activity in children and young people has become a very serious social problem in recent years, which negatively intervenes in a great number of areas of children's development. The movement regimen of children is influenced by a whole range of effects and stimuli. The influence of the family and its manners of leisure time spending undoubtedly has a very strong impact. School physical education and optional physical activities in schools are other elements that can influence the relationship of children to movement. We are glad that municipal policy authorities (such as school authorities) are also gradually engaged in the issues of the level of physical fitness in the Czech Republic. These authorities may partially affect the movement regimen of pupils during classes.
The goal of our research is to assess the motor development of children in the space of four years. We wanted to know if there is any difference between physically active children, who are regularly involved in sports, at least twice a week, in the form of organised physical activity, and children who are involved in sports less often, or not at all.

Methods:
The research sample consisted of 175 probands, of which were 88 girls and 87 were boys.
The first measurement was conducted in pupils from the 1st grade of primary school, roughly among the pupils in the age range of 6-7 years. The second measurement was conducted in the same pupils from the 5th grade, in the age range of 10-11 years. The research sample was divided into four groups: pupils who were not physically active either in the 1st grade or in the 5th grade (n1=26), pupils who were physically active in the 1st grade, but not in the 5th grade (n2=9), pupils who were not physically active in the 1st grade, but are physically active in the 5th grade (n3=30), and pupils who were physically active on an ongoing basis over the whole period of this research (n4=110).
The motion assumptions of these pupils were objectified using the German motor performance test DMT6-18. This battery consists of eight motor performance tests, namely: 20-metre sprint, Balancing backwards, Jumping sideways, Modified push-ups, Sit-ups, Deep forward bend, Standing long jump, and Six-minute run. Each of these tests was oriented towards assessing the level of different motor performance skills. The Kruskal-Wallis test was used to compare the intergroup results and substantive significance η2 was calculated from the H criteria.

Results:
The Kruskal-Wallis analysis showed that pupils from the 1st grade who are physically active on an ongoing basis can achieve significantly and objectively better results in the 20-metre sprint, Jumping sideways, Standing long jump, and Six-minute run tests. When testing pupils in the 5th grade, in addition to the above-mentioned tests, we added the Modified push-ups and Sit-ups tests.

Conclusion:
The results of our research point out to the fact that there are significant differences between physically active and physically inactive children already in the younger school age, especially in the tests that objectify speed ability, dynamic and explosive strength, and endurance. All the above-mentioned abilities are part of health-oriented fitness, associated with cardiovascular and muscular fitness, and they affect the health condition of people at a later age.

Keywords:

Motion abilities, primary school, physical activity, physical inactivity.