The Relationship between Vertical Jumping Performance and Isokinetic Strength of the Knee Extensors and Ankle Plantar Flexors in Basketball Players of Developmental Ages

Abstract

The relation between various factors of athletic performance and the appropriate method that these should be evaluated has been extensively discussed for many years. The purpose of this study was to investigate the relationship between maximum isokinetic strength of the knee extensors and ankle plantar flexors muscles and vertical jumping ability in young basketball players. One hundred-eighty young basketball players aged from 12 to 17 yrs volunteered to participate in the present study. Vertical jumping ability was measured using a squat jump (SJ), a counter movement jump (CMJ) and a counter movement jump with free hands (CMJHF) while for the isokinetic strength were evaluated the maximum isokinetic knee extension and ankle plantar flexion in 180 and 90ο/s respectively. The Pearson’s correlation coefficient was used to examine the relationship between isokinetic strength and vertical jumping ability and a regression analysis was used to explore the prediction of vertical jumping performance by isokinetic performance. The results showed a medium to high correlation between isokinetic strength and vertical jumping ability. In conclusion, isokinetic evaluation of isolated muscle groups that play a crucial role in performance can help considerably in planning and guidance of the training process.