## 3 Results  
The first part of the analysis involved intergroup comparisons. In most cases, the data distributions are normal (\(p\)\(>\) 0.05), and in a few cases, they are close to normal. Therefore, a parametric analysis of variance with repeated measures was used. Due to extreme asymmetries in the data distribution, a non-parametric equivalent was used for some of the viscoelastic properties of muscle. Significant differences were found for the main effects of the 5 m variable pre-post (F = 16.476; \(p\)\(<\) 0.01; \(\eta\)2 = 0.47). In contrast, no significant differences were found for the group effect (F = 1.090; \(p\)\(>\) 0.05) and the higher-order pre-post\"group interaction (F = 2.128; \(p\)\(>\) 0.05). To determine which groups had significant differences, further analyses were conducted using [PERSON]'s post-hoc multiple comparison tests. Significant differences \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Experimental Group**} & \multicolumn{2}{c}{**Control Group**} \\ \cline{2-5}  & **Pre** & **Post** & **Pre** & **Post** \\ \cline{2-5}  & **M \(\pm\) SD** & **M \(\pm\) SD** & **M \(\pm\) SD** & **M \(\pm\) SD** \\  & **(\(-95\%\); +95\%)** & **(\(-95\%\); +95\%)** & **(\(-95\%\); +95\%)** & **(\(-95\%\); +95\%)** \\ \hline \multirow{2}{*}{**RSI \({}^{\ddagger}\),*} & 1.48 \(\pm\) 1.42 & 1.69 \(\pm\) 1.68 & 1.19 \(\pm\) 1.35 & 1.24 \(\pm\) 1.28 \\  & (0.15; 0.40) & (0.17; 0.46) & (0.22; 0.58) & (0.21; 0.57) \\ \hline \multirow{2}{*}{**5 m [s] \({}^{\ddagger}\)**} & 1.09 \(\pm\) 1.11 & 1.01 \(\pm\) 1.02 & 1.10 \(\pm\) 1.12 & 1.06 \(\pm\) 1.07 \\  & (0.04; 0.12) & (0.03; 0.10) & (0.05; 0.15) & (0.04; 0.13) \\ \hline \multirow{2}{*}{**30 m [s] \({}^{\ddagger}\)**} & 4.30 \(\pm\) 4.33 & 4.13 \(\pm\) 4.18 & 4.36 \(\pm\) 4.43 & 4.28 \(\pm\) 4.30 \\  & (0.10; 0.28) & (0.10; 0.28) & (0.14; 0.38) & (0.09; 0.25) \\ \hline \multirow{2}{*}{**RF F [Hz]**} & 15.61 \(\pm\) 15.30 & 15.45 \(\pm\) 15.25 & 15.39 \(\pm\) 15.55 & 15.21 \(\pm\) 15.20 \\  & (0.88; 2.36) & (0.81; 2.16) & (0.59; 1.58) & (0.60; 1.61) \\ \hline \multirow{2}{*}{**RF S [N/m]**} & 281.90 \(\pm\) 274.00 & 271.90 \(\pm\) 274.00 & 275.70 \(\pm\) 275.50 & 273.90 \(\pm\) 276.00 \\  & (26.91; 71.45) & (22.87; 60.71) & (12.28; 32.60) & (12.27; 32.58) \\ \hline \multirow{2}{*}{**RF D [N/m] \({}^{\ddagger}\)**} & 1.51 \(\pm\) 1.54 & 1.40 \(\pm\) 1.40 & 1.42 \(\pm\) 1.43 & 1.38 \(\pm\) 1.33 \\  & (0.17; 0.47) & (0.19; 0.53) & (0.20; 0.53) & (0.16; 0.43) \\ \hline \multirow{2}{*}{**VL F [Hz]**} & 18.74 \(\pm\) 3.31 & 15.87 \(\pm\) 14.38 & 19.02 \(\pm\) 18.40 & 17.04 \(\pm\) 15.56 \\  & (2.52; 4.84) & (1.43; 3.79) & (2.47; 6.55) & (1.41; 3.76) \\ \hline \multirow{2}{*}{**VL S [N/m]**} & 346.30 \(\pm\) 321.50 & 291.60 \(\pm\) 264.48 & 345.40 \(\pm\) 333.00 & 311.70 \(\pm\) 291.90 \\  & (52.00; 138.03) & (26.07; 69.19) & (35.71; 94.78) & (19.03; 50.52) \\ \hline \multirow{2}{*}{**VL D [N/m]**} & 1.59 \(\pm\) 1.47 & 1.35 \(\pm\) 1.14 & 1.70 \(\pm\) 1.47 & 1.53 \(\pm\) 1.40 \\  & (0.11; 0.29) & (0.19; 0.52) & (0.01; 0.31) & (0.12; 0.33) \\ \hline \end{tabular}  
* RF--ectrus femoris; VL--vastus lateralis; F--tension; S--stiffness; D--elasticity; \({}^{\ddagger}\)--intragroup difference; \({}^{\star}\)--intergroup difference.  
\end{table} 
Table 4: Basic descriptive statistics. were found in the 5 m [s.] variable after and before the intervention in the experimental group (\(p<0.01\); df = \(-0.087\) (\(-8.6\%\)); ES = 1.44). These results are supported by the data presented in Figure 8.  
Significant differences were found for the main effects of the 30 m variable pre-post (F = 37.81; \(p<0.01\); \(\eta 2=0.67\)). In contrast, no significant differences were found for the effect group (F = 2.14; \(p>0.05\)). However, for the interaction group*pre-post, analysis of variance allowed us to reject the null hypothesis of no difference (F = 5.5; \(p<0.05\); \(\eta 2=0.23\)).