## 4 Discussion  
The first aim of our study was to investigate differences in strength capacities of elbow extensors and volar flexors and shooting performance between junior and senior basketball players. Our results showed similar \(\mathrm{k_{RTD-SF}}\) of both muscle groups between juniors and seniors regardless of significant differences between the two groups regarding training history, body mass and BMI. Similar values were also observed for \(\mathrm{T_{MVC}}\) of both groups, while juniors had significantly greater \(\mathrm{RTD_{PEAK}}\) (normalized to body weight). Seniors showed better shooting performance only at short distance compared to junior players. The second aim was to investigate associations between strength capacities and shooting performance. Significant associations between \(\mathrm{k_{RTD-SF}}\) of both muscle groups and shooting performance were found only in juniors. Our results revealed significant positive association between \(\mathrm{k_{RTD-SF}}\) of elbow extensors, volar flexors and shooting performance from short distance. On the contrary, a significant negative large association was found between \(\mathrm{k_{RTD-SF}}\) of both muscle groups and shooting performance from long distance. \(\mathrm{T_{MVC}}\) of elbow extensors was found to have a significant positive large association with shooting performance from long distance. Our third aim was to investigate associations in \(\mathrm{k_{RTD-SF}}\) of elbow extensors and volar flexors. Our results showed significant positive large associations between \(\mathrm{k_{RTD-SF}}\) of elbow extensors and volar flexors. In this study, we investigated the \(\mathrm{k_{RTD-SF}}\), \(\mathrm{T_{MVC}}\), and \(\mathrm{RTD_{PEAK}}\) of two major groups of arm muscles that generate force that is necessary for the execution of the basketball shot. RTD-SF has already been shown to be sensitive to changes in neuromuscular function associated with age [2] and disease [6]. As it was shown that explosive strength training positively influences shooting accuracy in basketball players [7], and moreover, there are some indices that maximum strength of elbow extensors is positively associated with shooting accuracy in the three-point shot, our goal was to further investigate the relationship between upper limb strength capacity and shooting performance. We hypothesized that a sport-specific movement that is constantly repeated (such as basketball shooting) might have an influence on strength capacities (\(\mathrm{k_{RTD-SF}}\), \(\mathrm{T_{MVC}}\), and \(\mathrm{RTD_{PEAK}}\)) of the responsible muscle groups, and in addition, it might be dependent on the training history and physical development. On this basis, we evaluated differences between junior and senior basketball players in terms of \(\mathrm{k_{RTD-SF}}\), \(\mathrm{T_{MVC}}\)  
Figure 4: Associations between \(\mathrm{k_{RTD-SF}}\) (**a–d**), \(\mathrm{T_{MVC}}\) (**e,f**) of elbow extensors (EE) or volar flexors (VF) and shooting performance from short and long distance. and RTDPEAK of EE and VF. The senior basketball players had significantly longer participation in basketball training and consequently greater experience and completed maturation. Previous studies have shown that players with more training experience had better free-throw performance compared to less-experienced players [12; 14]. Moreover, it was shown that explosive strength training of upper and lower limb improves basketball shooting accuracy [7]. In our study, we investigated shooting performance from shorter and longer, as different shooting distances may require different involvement of muscle strength capacities. Although it is known that muscle growth is occurring in boys until 17.5 years of age [19], our results showed that juniors and seniors had similar strength capacities of elbow extensors and volar flexors, with the exception of RTDPEAK.