The effect of isokinetic exercise training on knee muscle strength after 4 months of anterior cruciate ligament reconstruction

The aim of this study was to investigate the effect of isokinetic exercise training given in the 4th month and continued for 8 weeks on knee muscle strength in individuals undergoing anterior cruciate ligament (ACL) reconstruction. Twenty individuals who underwent ACL reconstruction with hamstring graft were included in the study (age: 30.85± 9.10 yrs, height: 178.90±9.38 cm, bmi: 25.66±2.93 kg/m²). Individuals were taken to exercise training by evaluating in the isokinetic system in the 16th weeks after the reconstruction and the test was repeated in the 24th weeks. Muscle strength assessment was performed in the isokinetic system (ISOMED 2000), at angular speeds of 60 º/sec (5 repetitions) and 180 º/sec (10 repetitions). Peak Torque Hamstring/Body weight, Peak Torque Quadriceps/Body weight, Hamstring/Quadriceps ratio were evaluated. Hamstring concentric-quadriceps concentric, hamstring isometric, quadriceps isometric, stability-coordination training was given 3 days a week for 8 weeks. All data were analyzed using SPSS 21 software. Paired T-test was used to determine the differences before and after training. As a result of the study, concentric hamstring strength was found to be greater at 24th weeks than at 16th weeks in the operated knee (p=0,000) and non-operated knee (p=0,003) at an angular speed of 60º/sec, and in the non-operated knee (p=0,000) at an angular speed of 180º/sec. There was no difference in concentric hamstring value between the times in the operated knee at 180 angular speeds (p>0,05). Concentric quadriceps strength was found to be greater at 24th weeks than 16th weeks in the operated (p=0.000) and non-operated (p>0,05) knee at an angular speed of 60 º/sec, in the operated (p=0.000) and non-operated knee (p=0.05) at an angular speed of 180º/sec. It was observed that the concentric hamstring/quadriceps ratio decreased at angular speed of 60º/sec in the operated knee in the 24th week compared to the 16th week, while this ratio increased in the non-operated knee (p>0,05). It was observed that concentric H/Q ratio in operated and non-operated knee, at an angular speed of 180°/sec. decreased in the 24th week compared to the 16th week (p>0,05). In conclusion, it was found that isokinetic training given from the 16th week to the 24th week was effective in increasing muscular strength after ACL reconstruction.