Comparison of eccentric and concentric isokinetic exercise testing after anterior cruciate ligament reconstruction

Evaluation of muscle function can be helpful in rehabilitation programs wit h knee injuries. The purposes of this study were to evaluate muscle perform ance and functional level through eccentric and concentric isokinetic testi ng after anterior cruciate ligament reconstruction, and to determine whethe r eccentric and concentric isokinetic values were correlated with functiona l level using the Modified Cincinnati Scale (MCS). In order to compare the characteristics of eccentric and concentric parameters, we tested 24 male p atients (mean age; 31.1 years) after primary reconstruction of ruptured ant erior cruciate ligaments of the knee (mean duration; 20.2 months), at angul ar velocities of 60 degree/sec using Cybex 6000 isokinetic dynamometer. We also evaluated the functional level using the MCS. The values of peak torqu e of the involved knee extensors and flexors were significantly lower than the uninvolved limb in all eccentric and concentric tests (p<0.01). The def iciency ratios of peak torque in knee extensors were significantly larger t han knee flexors in both eccentric and concentric tests (p<0.01). The MCS w as inversely correlated with the deficiency ratio in peak torque of eccentr ic knee ex-censors (p<0.05). These results suggest that eccentric knee exte nsor training is essential to rescore the functional capacity of the injure d knee and that isokinetic evaluation is necessary to plan rehabilitation p rograms to correct possible imbalances which may be predispose subjects to future injury.