The purpose of this study was to determine the relationship between isokinetic strength of the knee extensors at different range of motion and jump performance. Twenty-five subjects participated in this study. All subjects performed five maximal knee extensor efforts at angular velocity of 120º/s under three range of motion (90º~60º, 90º~30º, 90º~0º) on Cybex6000 Dynamometer. The subjects also performed counter-movement jump on Kistler9287 force platform. Pearson Product Moment Correlation analyses were conducted to determine the relationship between isokinetic strength and jump parameters. The significance level was set at α=.05. The average torque at 90º~60º, 90º~30º and 90º~0º of range of motion were 156.2Nm±38.17, 160.5 Nm±36.01, 165.6 Nm±44.27, respectively. The average jump height was 46.2±3.39. These correlation coefficients of isokinetic strength at three range of motion and jump performance were r=.406(p＜.05), r=.346(p＜.05), r=.046(p＞.05), respectively. In conclusion, the results of this study indicated there are significant relationships between isokinetic strength at two range of motion (90º~60º & 90º~30º) and jump performance.
