In this research we attempted to define the procedure which could be used to provide optimally distinct groups of school children in terms of the morphological structure of their bodies, and which could further be used to define the possible differences in explosive and repetitive strength. With this aim in mind, a sample of 269 school children aged 12±6 months were included in a study where three of their morphological measures were taken (body height, body mass, skinfolds) and five motor tests for the evaluation of explosive and repetitive strength carried out. First the K-means cluster analyses were used to define three distinct groups of participants in each individual morphological segment, with low, average, and high values. On the basis of the maximal number of possible combinations of previously defined groups from the overall sample of school children, three groups with different morphological structures of the body were determined, including: 104 school children with low values, 113 school children with average values and 52 school children with high values for all three morphological measurements. These defined groups of school children were used to determine the possible differences in the tests of explosive and repetitive strength.
On the basis of the obtained results we can conclude that the group with low values of morphological indicators (height, body mass, skinfolds) achieved the best results on the test for the evaluation of repetitive strength of the arms (MSKL), the group with average values on the tests for the evaluation of explosive strength (MSDM and MT20V), while for the rest of the tests there was no statistically significant difference between the distinct groups. The definition of the potential possibilities for the manifestation of certain motor skills, on the basis of these morphological indicators for each age category of school children, would be made possible through the application of a small number of anthropometric measures. The classification of a certain child into a suitable (appropriate for his affinities) group would enable the realization of a special work program which would enable the most effective improvement of his qualities.
