Results

The first stage of the research aimed at estimating the level of the indicators of maximal power of the lower limbs as well as their correlation to the score received for the front handspring vault (Table 1). The highest correlation coefficient was observed in the Maximal Power indicator (r = 0.401, p < 0.05), with the mean value of 1400.91 ± 502.74 W. The correlation of the Relative Maximal Force indicator was slightly lower and reached r = 0.330 with the mean value of 234.87 ± 34.34 %BW. The most significant correlation was found between Jump Height and Flight Time (r = 0.324, x¯ = 0.26 ± 0.04 cm). An adverse correlation was observed between Time and Maximal Force; however, it was statistically irrelevant.

Mean values of lower limb power indicators and their correlation to the score received

BW – body weight,

The second stage of the research aimed at estimating the level of biomechanical indicators of the front handspring vault as well as their correlation to the score received (Table 2). The judges’ scores for the performed front handspring vault reached 13.38 ± 1.02 points. What proved to exert the highest impact on the judges’ scores was the angle of the hip joint during the second phase of the flight (r = -0.671). The mean value of the mentioned indicator reached 196 ± 16.64°. A significant correlation was also observed with the duration of hands' touching the vault surface (r = -0.63, X¯ = 0.26 ± 0.12 s), in the flight height in the second phase of the flight with respect to the vault (r = 0.602, X¯ = 41.74 ± 15.79 cm) and also in the landing distance (r = 0.631, X¯ = 138.73 ± 45.79 cm). Other indicators proved to be of statistical significance with regard to the correlation to the final scores received i.e., the run-up speed (r = 0.54, x¯ = 5.92 ± 0.47 s), the spring distance before the vault (r = 0.441, x¯ = 96.64 ± 22.78 cm), the height in the first phase of the flight (r = 0.468, x¯ = 43.15 ± 10.89 cm), the angle of the hip joint when hands touched the vault surface (r = 0.554, x¯ = 164.33 ± 23.08) and the difference in height between the first and the second phase of the flight (r = 0.410, x¯ = 1.38 ± 11.34 cm). The angle in the hip joint in the first phase of the flight as well as the upper limb absolute angle at hand contact with the vaulting table were not significantly related to the judges’ scores.

Mean values of biomechanical indicators and their correlation to the score received

The last stage of the research consisted of conducting multiple regression analysis by means of backward stepwise regression in order to predict the performance level of the front handspring vault (Table 3). The judges’ scores were the explained variable and the explanatory variables were: the value of the researched indicators of the lower limbs’ maximal power, kinematic analysis and the selected indicators of physical abilities. The programme automatically incorporated these variables into the equation that mostly influenced the searched value, eliminating those that presented multicollinearity with other explanatory variables. The received model of the assessment considered only two kinematic variables, as they proved to be the most crucial ones for receiving a high score: the angle of the hip joint in the second phase of the flight (p < 0.001) and the angle of the hip joint when hands touched the vault surface (p < 0.05).

Dependent variable regression results: the score for the handspring

Statistics of the regression: r = 0.713, r² = 0.51, F(2,39) = 20.18, p<0.0001.

Std. Error of Estimation = 0.74, f² = 0.351

Hip angle during contact: angle of the hip joint at hand contact with the vaulting table;

Hip angle in the 2^nd phase: angle of the hip joint in the second phase of flight

The multiple regression formula, equation (1), was developed to predict the potential score that a gymnast could receive for the front handspring vault.

α2 - the angle of the hip joint in the second phase of the flight [°]

γ1 - the angle of the hip joint at hand contact with the vaulting table [°]