## 3 Results  
The reliability of the outcome variables is shown in Table 2. For both muscle groups RTD-SF and T\({}_{\text{MVC}}\) showed very good reliability (all ICC \(\geq\) 0.85; all CV \(\leq\) 5.66%); however, the reliability was somewhat lower for RTD\({}_{\text{PEAK}}\), especially for the VF muscles (ICC = 0.54; CV = 15.21%). Junior players had a significantly lower average number of training years (\(5.5\pm 1.8\) years) compared to senior players (\(14.1\pm 3.8\) years) (t\({}_{(21)}=-7.2\), \(p<0.013\)). There was no statistically significant difference in height between groups (t\({}_{(21)}=-1.6\), \(p=0.11\)), while senior players had statistically significantly higher body mass (t\({}_{(21)}=-3.4\), \(p=0.003\)) and body mass index (BMI)(t\({}_{(21)}=-3.0\), \(p=0.007\)). Average kRTD-SF, T\({}_{\text{MVC}}\), and RTD\({}_{\text{PEAK}}\) values of elbow extensors and polar flexors in junior and senior group are presented in Table 3. Junior and senior players had similar values of T\({}_{\text{MVC}}\) in both muscle groups, while junior players had significantly greater RTD\({}_{\text{PEAK}}\) of EE and VF (\(p=0.003\)-0.005, ES = 0.35-0.36). For both groups, a strong linear relationship (r\({}^{2}\)RTD-SF = 0.93-0.95) between the peak force and the RFD across submaximal contractions was calculated for both muscle groups (sample recordings are presented in Figure 3). There was no statistically significant difference in kRTD-SF between junior and senior players for elbow extensors or volar flexors. There was no difference in shooting performance from long distance, whereas senior players were more successful from short distance. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{**Muscle Group/Variable**} & **ICC** & **CV** \\ \hline \multirow{4}{*}{Elbow extensors} & T\({}_{\text{MVC}}\) & 0.91 (0.85–0.96) & 2.34 (1.02–3.49) \\  & RTD\({}_{\text{PEAK}}\) & 0.78 (0.55–0.92) & 7.89 (3.44–12.75) \\  & k\({}_{\text{RFD-SF}}\) & 0.99 (0.97–1.00) & 1.23 (0.97–2.03) \\  & r\({}^{2}\)RFD-SF & 0.88 (0.76–0.96) & 1.05 (0.54–1.61) \\ \hline \multirow{4}{*}{Volar flexors} & T\({}_{\text{MVC}}\) & 0.85 (0.72–0.94) & 5.66 (2.81–8.44) \\  & RTD\({}_{\text{PEAK}}\) & 0.54 (0.23–0.84) & 15.211 (8.76–21.12) \\  & k\({}_{\text{RFD-SF}}\) & 0.99 (0.96–1.00) & 1.71 (1.11–2.58) \\ \cline{1-1}  & r\({}^{2}\)RFD-SF & 0.87 (0.67–0.96) & 5.45 (2.36–9.21) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Reliability of the outcome variables. Significant associations between \(\rm k_{RTD\text{-}SF}\), \(\rm T_{MVC}\), \(\rm RTD_{PEAK}\) (EE and VF) with shooting performance for junior players are presented in Figure 4. We calculated a large positive association between \(\rm k_{RTD\text{-}SF}\) of EE and VF and shooting performance from short distance (Figure 4a,b), while significant negative large associations were seen between \(\rm k_{RTD\text{-}SF}\) of both muscle groups and shooting performance from long distance (Figure 4c,d). Moreover, a significant positive large association was calculated between \(\rm T_{MVC}\) of EE and shooting performance from long distance (Figure 4e), while the association between \(\rm T_{MVC}\) of VF and shooting performance was not statistically significant (Figure 4f). No statistically significant associations were calculated in junior players between \(\rm RTD_{PEAK}\) of both muscle groups and shooting performance (r = 0.246-0.315, \(p\) = 0.48-0.49). There were no significant associations between \(\rm T_{MVC}\), \(\rm RTD_{PEAK}\), or \(\rm k_{RTD\text{-}SF}\) (EE and VF) and any shooting performance in senior basketball players (r = -0.481-0.481, \(p\) = 0.15-0.55) or in both groups combined (r = -0.366-0.271, \(p\) = 0.16-0.87).