## 4 Discussion
However, past data on joint behavior during the BS motor action are still lacking, making it difficult to compare to previous results. Meanwhile, strength has been described as a crucial capacity for generating the impulse needed to throw the ball. Players who are less able to generate force, such as females and children, have a more challenging time while shooting [2]. Therefore, it is essential to understand the relationship between the shooting motor action and the shooter's anthropometric and fitness characteristics. To the best of our knowledge, this is the first study to consider this type of analysis. According to our results, the ball release height showed the highest number of relationships independently of the ball size. Past literature suggests that a strong and positive correlation exists between ball release height and stature [31]. Body mass also displayed a strong and positive relationship with ball release height (r = \(>\) 0.71 \(<\) 0.77), which is likely related to strength. Indeed, both the handgrip and the 2 kg ball throw presented strong correlations with ball release height (positive), ball release angle (negative), and the peak angular velocities of joints. Strength likely contributes to generating ball velocity, and if velocity increases, the angle at ball release should decrease, which would justify the negative correlation between the 2 kg ball throw and the ball release angle. Thus, upper-body strength appears to be an important predictor of ball trajectory. In contrast, the CMJ was significantly and negatively related to the ball release height. A linear and positive correlation between both variables would be expected; however, this result must be interpreted together with the other variables in the analysis. In fact, the literature has described the positive relationship between body mass and strength during the adolescent years and the detrimental effect of body mass in jumping tasks [3]. Overall, our results underline upper-body strength as a crucial variable for the performance of the shooting motor action, as previously suggested in the literature [1,2]. In addition, it may contribute to raising awareness among sports agents and coaches regarding promoting strength development in the basketball training process as part of supporting a shooter's improvement. The overall assessment of the kinematic parameters shows a slight variation in the performance of the shooting motor action according to the ball size used, which is insignificant in affecting shooting efficacy. Indeed, efficacy is a product of the ball's trajectory, and the ball's trajectory is defined by the angle, velocity, and height at release [15]. Note that the ball release variables did not significantly vary between shooting conditions. Thus, our results suggest that the movement pattern used was consistent and not immediately affected by short-term changes in ball characteristics. This is also reflected by the ratio between scored and missed attempts. The results of the current study have important practical implications for those working with young people at the early stages of basketball-specific skills development. Although the sample size and the 2D analysis represent limitations in this study, the results showed that the manipulation of ball size did not significantly affect shooting performance. Therefore, the BS teaching process may not be limited to the standardized rules regarding ball size and weight for a specific age group, and adaptations could be made according to participants' anthropometric features or basketball experience level. This strategy could be helpful in the acquisition of optimal shooting patterns, enhancing efficacy and enjoyment among youth basketball players. Moreover, the relationships between the handgrip and the 2 kg ball throw with the selected kinematic parameters indicate the crucial contribution of upper-body strength to motor action performance.