Jumping ability and kinetic knee extensors' performance in elite soccer players

The aim of the present study was to determine the relationship between vertical jump performance and the isokinetic strength of the knee extensors in elite soccer players. Thirty-six elite players participated in the present study. The peak jumping height (of the squat and counter movement jumps on an Ergojump device) was used as indicator of vertical jump performance. The subjects also performed three submaximal and three maximal isokinetic efforts of the knee extensors at angular velocities of 60, 180 and 240 degrees/s. Pearson product moment correlation analyses were conducted to determine the relationship between isokinetic strength and jumping parameters. The significance level was set at p<0.05. The analysis indicated that jumping height was highly to moderately correlated with the knee torques at the test velocities after the preparatory period.