Association between isokinetic knee strength and quality of life, return to sports and activities of daily living in recreational athletes undergoing anterior cruciate ligament reconstruction

The aim of this study was to compare the isokinetic knee muscle strength between patients who had anterior cruciate ligament reconstruction (ACL-R) with autogenous hamstring tendon graft at least postoperative 1 year and healthy individuals of the same age, and to investigate the correlation between isokinetic muscle strength and quality of life, return to sport and daily living activities of patients with ACL-R. Twenty-three male patients aged 18-40 years with at least postoperative 1 year and as 23 healthy male subjects as control group were included in the study. The muscular strength of the individuals assessed with ISOMED 2000 isokinetic dynamometer, quality of life assessed with Anterior Cruciate Ligament Quality of Life Questionnaire (ACL-QOL), return to sports assessed with Anterior Cruciate Ligament Return to Sport After Injury Questionnaire (ACL-RSI) and daily activities assessed with Forgotten Joint Score-12 (FJS-12). At angular velocities of 60°/s and 180°/s; hamstring muscle strength and endurance in ACL-R group were lower than the control group (p=0.035; p=0.029); at 60°/s angular velocity, there was no difference in the strength of quadriceps femoris muscle between the groups (p=0.173) and at 180°/s angular velocity, quadriceps femoris muscle endurance in ACL-R group was lower than control group (p = 0.036). In ACL-R group, ACL-QOL, ACL-RSI and FJS-12 scores were lower than in the literature. In ACL-R group, at 60°/s and 180°/s angular velocities, there was no correlation between quadriceps femoris and hamstring muscle strength and return to sports (ACL-RSI) scores (r=-0.269, p=0.215; r=-0.277, p=0.201; r=-0.231, p=0.288; r=-0.271, p=0.211). There was also no correlation between muscle strength and quality of life (ACL-QOL) scores (r=-0.034, p=0.879; r=-0.235, p=0.280; r=-0.024, p=0.914; r=-0.259, p=0.233); and daily living activity (FJS-12) scores (r=-0.333, p=0.121; r=-0.244, p=0.263; r=-0.083, p=0.706; r=-0.179, p=0.414). In conclusion, considering the long-term results of individuals after ACL-R; in the rehabilitation process, it is not enough to improve only muscle strength, but it is also necessary to encourage individuals to be psychologically ready to return to sports, to improve their quality of life and to contribute to adaptation to daily life by minimizing joint awareness.