This study compares force profiles during multi-joint isokinetic leg extensions with the knee-hip extension phase of the countermovement jump (CMJ) in 12 long jump athletes. Isokinetic leg press movements were performed at two different velocities (0.1 m/s and 0.7 m/s), and CMJs were measured on dual force plates. Force profiles were analyzed using Statistical Parametric Mapping to assess the temporal dynamics of force generation. Additionally, bilateral force differences between the legs for each condition were examined. The results indicate that isokinetic conditions (0.1 m/s and 0.7 m/s) differ significantly from the vertical jump in terms of force profiles. Furthermore, significant differences were observed between the force profiles at the two isokinetic speeds. In contrast, bilateral force differences showed high variability and no significant differences, suggesting that side-to-side force production is highly variable. These findings highlight that movement velocity during isokinetic exercises influences force-generation patterns differently than it does in dynamic, explosive movements like the CMJ. The high variability in bilateral differences suggests the complexity of force production in athletes, warranting further research. This study provides novel insights into the temporal structure of force production and the importance of movement velocity in the transferability of strength training to dynamic, sport-specific movements.

Force Production, Lower Extremity, Jump Performance