The impact of a isokinetic training program on the peak torque of the quadriceps and knee flexors after anterior cruciate ligament reconstruction with hamstrings.

BACKGROUND The purpose of this study was to evaluate the peak torque of the knee flexors (H) and the quadriceps muscle (Q) at 12 and 24 weeks after isolated anterior cruciate ligament reconstruction with semitendinosus and gracilis autografts. MATERIALS AND METHODS There were 20 patients (8 females, 12 males), with the mean age of 31.5 years. An isokinetic examination of the muscles was performed with a Biodex System 3 isokinetic dynamometer at a speed of 180 degrees/sec. All patients underwent 12 weeks of isokinetic training for 20 minutes 5 times a week (240 degrees/sec for 6 weeks and 180 degrees/sec for 6 weeks) beginning 12 weeks after surgery. RESULTS The average peak torque difference between the healthy and operated limb at 12 and 24 weeks postoperatively was 38% and 14% for Q and 25% and 4.3% for H respectively. The decrease in peak torque differences was statistically significant for both H and Q (p=0.05). The decrease in Q peak torque was significantly higher than that of H peak torque 12 and 24 weeks after surgery. CONCLUSIONS These results indicate that 12-week isokinetic training can increase the peak torque of H and Q by 20% and 24% respectively. An isokinetic examination of Q and H peak torques should become a standard procedure for evidence-based monitoring of the rehabilitation process after anterior cruciate ligament reconstruction.