Research Summary: Eccentric rate of force development determines jumping performance

G. Laffaye and P. Wagner. Eccentric rate of force development determines jumping performance. Computer Methods in Biomechanics and Biomedical Engineering, 2013 Vol. 16, No. S1, 1–2.

Key Takeaways

• LOAD is positively correlated with JUMP HEIGHT r = 0.50

• EXPLODE is positively correlated with JUMP HEIGHT r = 0.54

• Impulse method is more accurate than flight time method for measuring JUMP HEIGHT

• LOAD is more accurate than Peak Concentric RFD at predicting JUMP HEIGHT

“This study is the first one which demonstrates that the average eccentric RFD is a strong predictor, better than the peak RFD or the concentric RFD”

POPULATION: The sample was composed of 178 males, all skilled athletes (football, basketball and baseball) evolving in the national US championship.

Summary

The questions covered:

• What variable of the vertical jump best predicts jump height?

• How does this relate to previous research and findings?

Countermovement jumps (CMJ) of 178 males athletes were performed on a force platform and compared. The subjects consisted of all skilled athletes in the sports of football, basketball, and baseball.

The main result of this study suggests that maximal JUMP HEIGHT during CMJ is primarily determined by ECC – RFD (LOAD) and CON–VF (EXPLODE). The study found the increasing ECC-RFD and decreasing ECC-TIME were the most effective motor strategies to increase jump height in athletes. Increasing ECC-RFD and decreasing ECC-TIME improves the stretch shortening cycle and increases the elastic energy stored in the tendon, as well as activating the stretch reflex, thereby allowing an athlete to jump higher.

The present study is the first one that demonstrates that ECC-RFD is a stronger and more accurate predictor of JUMP HEIGHT than peak concentric RFD because it summarizes the capacity of the muscle-tendon unit structure to stretch quickly before attaining the peak of force.

Secondly, the method to measure the JUMP HEIGHT is more accurate in this study (impulse method) than the flight time method, which is associated with high errors due to the variation in the take off and the landing position.

Click here for the publication