Swimming Performance to 25 Meters Backstroke Depends on Selected Factors of Explosive Strength of Lower Limbs

The aim of our work was to analyze the partial shares of selected factors of explosive strength of lower limbs on the overall explanation of swimming performance to the 25 meters backstroke. 29 students of Physical Education took part in our research and completed 6 tests. These tests were realized on a dry-land and in the water and they consisted of swimming performance to 25 meters backstroke, swimming start speed to 4 meters, vertical jump with and without arm-swing, maximum and average velocity of take-off performance on dry land under the backstroke start conditions. The obtained data are described by descriptive statistics and all parameters were entered to the correlation analysis for their dependence evaluation. By the analysis, we found that all tests significantly correlated with each other (p < 0.01; p < 0.05) except for the start to 4 meters test and Tendo velocity average test. For the evaluation of factors that determine the swimming performance to 25 meters backstroke, we use the regression analysis of parameters where the regression model was reflected as statistically significant (R² = 0.479 %; SEE = 3.396 %). Partial shares of individual tests, except for tests of maximal and average velocity on a dryland, showed up as statistically significant (p < 0.05; p < 0.01), with the highest share of swimming start to 4 meters performance (p < 0.01; r = 0.686). We used the regression step analysis in which we decrease the indicators to the three main factors of the strength of lower limbs model, which influence the swimming performance to the 25 meters backstroke significantly with large effect (R² = 0.4787 %; f² = 0.9183; F = 7.652; p < 0.01). Again, the highest and statistically significant (p < 0.01) share on the explanation of swimming performance had the start to 4 meters with 43.33 % percentage share. Besides the swimming start, the Countermovement Jump test was statistically significant too (p < 0.05) and statistically insignificant was test of maximum velocity on a dry-land. By this study we can evaluate how individual factors of strength of lower limbs influence the swimming performance and for the future it is necessary to complete them with the other factors for the better creation of the appropriate swimming training program.