## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline  & & **SJ** & **CMJ** & **COD** & **COD\(\%\)** & **0-10 m** & **10-20 m** & **0-20 m** & **20-30 m** & **0-30 m** \\ \hline \multirow{4}{*}{**RSI**} & \(\beta\) & 0.523 & 0.605 & \(-\)0.485 & \(-\)0.642 & 0.698 & \(-\)0.317 & 0.423 & 0.334 & 0.404 \\ \cline{2-11}  & \(p\) & 0.038 & **0.013** & 0.057 & **0.007** & **0.003** & 0.232 & 0.103 & 0.206 & 0.121 \\ \cline{2-11}  & \(\mathbf{R}^{2}\) & 0.273 & 0.366 & 0.235 & 0.412 & 0.488 & 0.100 & 0.179 & 0.112 & 0.163 \\ \hline \multirow{4}{*}{**STIFFNESS**} & \(\beta\) & 0.123 & 0.351 & \(-\)0.112 & \(-\)0.348 & 0.502 & \(-\)0.437 & 0.233 & 0.171 & 0.218 \\ \cline{2-11}  & \(p\) & 0.650 & 0.182 & 0.679 & 0.187 & **0.048** & 0.091 & 0.385 & 0.525 & 0.417 \\ \cline{2-11}  & \(\mathbf{R}^{2}\) & 0.015 & 0.123 & 0.013 & 0.121 & 0.252 & 0.191 & 0.054 & 0.029 & 0.048 \\ \hline \multirow{4}{*}{**PSAP**} & \(\beta\) & 0.022 & 0.492 & 0.160 & \(-\)0.443 & 0.553 & 0.265 & 0.594 & 0.313 & 0.050 \\ \cline{2-11}  & \(p\) & 0.937 & 0.053 & 0.553 & 0.086 & 0.026 & 0.321 & **0.015** & 0.238 & 0.046 \\ \cline{1-1} \cline{2-11}  & \(\mathbf{R}^{2}\) & 0.000 & 0.242 & 0.026 & 0.196 & 0.306 & 0.070 & 0.353 & 0.098 & 0.256 \\ \hline \end{tabular} Note: Each predictor was analyzed in a separate simple linear regression model to examine its individual association with each performance variable. **EUR**: Eccentric Utilization Ratio; **PP**: Peak Power; **CONPF**: Concentric Peak Force; **ECCPP**: Eccentric Peak Power; **ECCPF**: Eccentric Peak Force; **RSI**: Reactive Strength Index; **PSAP**: Pre-stretch Augmentation Percentage.  
\end{table} 
Table 4: _Cont._finding is consistent with [PERSON] et al. (2022), who emphasized the critical role of eccentric force in change of direction deficit [32]. Similarly, the significant associations between peak power (PP) and all sprint phases, VJ, COD, and COD% suggest that high power output is a critical determinant of multidirectional athletic performance. In the context of sprinting, PP has been shown in the literature to relate to reduced ground contact time and increased external mechanical work during the acceleration phase [33]. Regarding vertical jump outcomes, PP reflects the capacity of the muscle-tendon unit to contract at high velocity within a short time, making it a primary determinant of jump height [34]. Moreover, the significant explanatory value of PP for COD performance suggests that high power production during the deceleration-to-acceleration cycle offers a performance advantage, indicating that COD ability depends not only on strength but also on the ability to generate high mechanical power rapidly. These findings align with previous studies highlighting PP as a critical performance determinant in short-duration, high-intensity movements such as sprinting, jumping, and COD tasks [35; 36; 37; 38]. The association between EUR and performance in female athletes may reflect their greater reliance on elastic properties and tendon compliance. In women, enhanced utilization of the eccentric phase could improve force transmission during early sprint acceleration and vertical displacement during jumping. This supports the notion that EUR may offer greater predictive value in female populations due to sex-specific neuromuscular and architectural characteristics. The observed links between RSI and performance in female athletes suggest that reactive strength plays a critical role in executing rapid, explosive movements. High RSI values indicate superior ability to generate force in minimal ground contact time, which is especially advantageous during short sprints and rapid directional changes. These findings emphasize the importance of pyrometric efficiency and stretch-shortening cycle function in enhancing both linear and multidirectional performance in female athletes. Eccentric strength parameters such as ECCMP, ECCPP, and ECCPF/BM also showed significant associations with early-phase sprint and VJ performance (\(p<0.05\)).