## 4 Discussion
### Relationship Between Kinematic Variables and Maximal and Explosive Hip Strength  
Hip abductor strength demonstrated a positive correlation with femur inclination (r = 0.27) and a negative correlation with hip angle (r = \(-\)0.23) in the sagittal plane. Hip abductors are most commonly associated with preventing the pelvis from dropping on the side of the unsupported leg in the frontal plane and, consequently, maintaining the alignment and stability of body segments (specifically pelvic and trunk stability), thereby enabling the lower limbs to adopt more mechanically favorable positions that optimize force production and stability during explosive tasks such as SLCMJs [18; 33; 34]. The negative correlation between hip abductor strength and hip angle in the sagittal plane may reflect a more stable and controlled movement strategy, where the athlete minimizes excessive motion in the hip joint to maintain balance and inter-segment alignment. This is in agreement with the study by [PERSON] et al. (2016) [35], where the authors demonstrated that participants with a lower jump performance showed greater trunk flexion at the end of the concentric phase, which could imply reduced lower-limb extension and, consequently, a shorter range of motion for force production during push-off. On the contrary, better jumpers exhibited a greater descent amplitude, which indicates a longer range of motion over which force can be produced, resulting in a greater push-off GRF impulse [35; 36]. The findings of this study underscore the importance of hip abductor strength for frontal plane pelvic stability and the optimization of sagittal plane jump technique. Weaknesses in these muscles could compromise trunk control and lower-limb alignment, potentially leading to compensatory movement patterns that reduce efficiency and increase the risk of injury [37; 38]. Nonetheless, practitioners should be careful when interpreting the results. Low-level correlations indicate that there could be other important factors that contribute to jump performance. Future research should explore targeted hip strength training interventions and the relationships of hip strength with sagittal plane kinematics and jump performance. A weak but significant (\(p\) < 0.05) positive correlation was found between hip abduction strength and frontal plane shin inclination (r = 0.226). This suggests that stronger athletes in our study may have adopted a jump strategy with greater shin inclination, potentially linked to a controlled knee valgus position. While valgus is often seen as an injury risk [39; 40; 41], in this context, it may reflect an efficient alignment for force production and energy transfer during propulsion. The weak correlation indicates that hip abduction strength is just one factor influencing jump technique, with neuromuscular coordination, ankle mechanics, and trunk stability likely also playing roles [19; 33; 42; 43]. Future research should determine whether this shin inclination enhances performance or is an adaptive response to individual biomechanics and identify when valgus transitions from functional to harmful. To the authors' knowledge, this is the first study to demonstrate a significant relationship between hip adductor RTD and trunk angle and trunk inclination kinematic variables during SLCMJs. A high RTD is known to be essential for a superior performance in both jumping [25] and sprinting [44]. Furthermore, executing single-leg movements with a high RTD requires strong and powerful hip adductor and adductor muscles [45; 46]. The adductor muscles contribute to hip stability by facilitating synergistic contractions with the intrapelvic musculature. Specifically, the hip adductor muscles work in coordination with the internal and external obliques as part of the anterior oblique sling system, ensuring both functional movement and trunk stabilization [47].