## 3 Results
### Countermovement Jump  
The ANOVA showed no statistically significant differences in the maximum CMJ height with respect to time and the three measurements (F(1,18) = 1.1, \(p\) = 0.368; Figure 4), and the interaction between groups and time (F(1,18) = 3.7, \(p\) = 0.053; Table 2).  
\begin{table}
\begin{tabular}{c c c c c c} \hline  & & **PRE** & **POST1** & **POST2** &
\begin{tabular}{c} _p_-Values/ES (np2) \\ Interaction \\ \end{tabular} \\ \hline Jump Height (cm) & Intervention & \(34.3\pm 3.3\) & \(35.2\pm 3.8\) & \(34.7\pm 4.3\) & \(0.462/0.613\) \\ Control & \(33.5\pm 4.1\) & \(34.5\pm 3.8\) & \(35.3\pm 3.7\) & \\ \hline Work Con (J) & Intervention & \(457.3\pm 58.8\) & \(463.2\pm 48.7\) & \(447.4\pm 52.5\) & \(0.231/0.124\) \\ Control & \(486.6\pm 35.8\) & \(478\pm 46.7\) & \(460.8\pm 43.5\) & \\ \hline Power Con (w) & Intervention & \(1589.9\pm 276.4\) & \(1602.5\pm 317.3\) & \(1595\pm 243.5\) & \(0.125/0.382\) \\ Control & \(1605.8\pm 246.4\) & \(1611\pm 367.6\) & \(1628.6\pm 213.3\) & \\ \hline \end{tabular}
\end{table}
Table 1: Squat Jump (SJ) performance for each condition, timepoint, and tests of within-subject contrasts.  
\begin{table}
\begin{tabular}{c c c c c c} \hline  & & **PRE** & **POST1** & **POST2** &
\begin{tabular}{c} _p_-Values/ES (np2) \\ Interaction \\ \end{tabular} \\ \hline Jump Height (cm) & Intervention & \(39.8\pm 3.1\) & \(37.2\pm 2.8\) & \(39.7\pm 3.3\) & \(0.368/0.523\) \\ Control & \(37.7\pm 3.1\) & \(38.3\pm 2.8\) & \(35.7\pm 3.3\) & \\ \hline Work Ecc (J) & Intervention & \(93.9\pm 11\) & \(101\pm 11.9\) & \(110.5\pm 9.9\) & \(0.505/0.133\) \\ Control & \(85.4\pm 11\) & \(99.2\pm 11.9\) & \(99.2\pm 9.9\) & \\ \hline Work Con (J) & Intervention & \(347.7\pm 28.8\) & \(354.2\pm 28.7\) & \(340.4\pm 30.5\) & \(0.101/0.114\) \\ Control & \(376.6\pm 28.8\) & \(379\pm 28.7\) & \(385.8\pm 30.5\) & \\ \hline Power Ecc (w) & Intervention & \(-2196\pm 109.9\) & \(-2230.1\pm 104.1\) & \(-2195.5\pm 110.7\) & \(0.177/0.134\) \\ Control & \(-2175\pm 109.9\) & \(-2225.2\pm 104.1\) & \(-2255.6\pm 110.7\) & \\ \hline Power Con (w) & Intervention & \(2341.9\pm 176.4\) & \(2379.5\pm 167.6\) & \(2249\pm 173.3\) & \(0.195/0.182\) \\ Control & \(2510.8\pm 176.4\) & \(2538\pm 167.6\) & \(2549.6\pm 173.3\) & \\ \hline Lower Leg & Intervention & \(26\pm 2.5\) & \(27.5\pm 2.6\) & \(27.5\pm 2.7\) & \(0.358/0.095\) \\ Stiffness (N/cm) & Control & \(25.7\pm 2.5\) & \(25.7\pm 2.6\) & \(26\pm 2.7\) & \\ \hline \end{tabular}
\end{table}
Table 2: Countermovement Jump (CMJ) performance for each condition, time point, and tests of within-subject contrasts.  
Figure 4: Jumping height (mean \(\pm\) SD) during CMJ (Countermovement Jump) at the three timepoints.  
The work during the eccentric phase revealed a significant main effect of time (F(2,18) = 9.9, \(p\) = 0.002). Post hoc pairwise comparisons using Bonferroni revealed a significant mean difference between PRE (M = 89.7 J) and POST1 (M = 100.1 J; \(p\) = 0.027) and between PRE and POST2 (M = 104.9; \(p\) = 0.008), while no significant mean difference was found between POST1 and POST2 (\(p\) = 0.562) for eccentric work (Figure 5). However, there was no interaction between group and time (F(2,18) = 0.7, \(p\) = 0.505; Table 2). In contrast, there was no statistically significant difference in produced concentric work in time (F(2,18) = 0.4, \(p\) = 0.708) and interaction (F(2,18) = 2.6, \(p\) = 0.101; Table 2). Power was not statistically different during the eccentric and concentric phases across time (Table 2) and all three measures (F(2,18) = 1.6, \(p\) = 0.236; F(2,18) = 1.9, \(p\) = 0.177, respectively) and the interaction between group and time (F(2,18) = 1.6, \(p\) = 0.237; F(2,18) = 1.8, \(p\) = 0.195, respectively). Finally, the lower limb stiffness during the eccentric phase did not show any statistical differences with time (F(2,18) = 1.2, \(p\) = 0.336) or the condition x time interaction (F(2,18) = 1.1, \(p\) = 0.358; Table 2).