# Examining the Link between Isokinetic Strength Metrics and Ball Speed in Women's Soccer
## 4 Discussion
However, the relationships between strength generated in the dominant direction and ball speeds were not significant. Previous reports had indicated a decrease in maximal torque at increased angular velocities [55]. Nevertheless, the 300\({}^{\circ}\)/s angular velocity tests the presence of explosive force at high speeds [42]. The outcome suggests that the maximum explosive force generated by a non-dominant extremity possessing a balanced agonist-antagonist ratio positively supports dominant extremity performance. This is significant since the final phase of force transmission is the contact phase with the ball, where the performance of the extremity remaining on the ground significantly affects kick performance. This study's findings underscore the importance of strong and balanced strength development in the non-dominant extremity. The relationships between isometric and eccentric contractions of players' generated strength and ball speed were found to be non-significant. Previous studies have reported high strength torque production during isometric and eccentric contractions [56]. Additionally, it has been noted that immediately after isometric, concentric, and eccentric exercises with the same torque-time integral, similar neuromuscular fatigue is induced. However, the force loss after isometric and eccentric exercises lasts longer than after concentric exercises, and changes in peripheral fatigue parameters are most significant after eccentric exercises [57]. These results indicate the advantages of isometric and eccentric exercises in terms of generated torque. However, the findings of our research study show that these high torques do not influence ball speed. Considering the importance of force transmission for athletic performance, it can be concluded that concentric exercises may be more beneficial for soccer. This is because in soccer, kicks are executed using concentric contractions of the lower extremities. Therefore, it is natural for the force produced through concentric contractions to be more dominant during ball kicks. Moreover, the findings suggest that force exercises tailored to the specific sport and related movements can be more usable and suitable for enhancing athletic performance. The relationships between players' time to peak torque during isokinetic strength measurement and ball speed were insignificant. This finding indicates that there is no significant association between the time to reach peak torque on the isokinetic dynamometer and the force generated during ball kicking. The reason for this outcome could be the potential discrepancies between strength production performance on the isokineticdynamometer and specific kicking performance in soccer [58]. Another factor could be that players may not reach their maximal strengths during ball kicking. In both cases, it appears that players exhibit different force-time profiles during isokinetic dynamo-etry compared to shot performance. While shot performance involves complete body biomechanics [15; 46], players focusing on maximal force production and adopting the appropriate position during isokinetic performance may not align with the biomechanics of kicking. Therefore, although there might be some similarities between the EXT movement on the isokinetic dynamometer and shot performance in terms of biomechanical aspects, the moment of delivering the kick and the moment of producing maximal strength may not coincide. This outcome underscores the need for employing more specific methods tailored to soccer-specific force and timing investigations. The findings of this research study generally indicate that concentric exercises designed at slow, moderate, and high angular velocities could enhance shot performance. Furthermore, the obtained results underscore the importance of giving equal consideration to the non-dominant extremity. However, certain precautions and additional tests are necessary to achieve more definitive conclusions.