Isokinetic Evaluation of Quadriceps and Hamstring Muscle Performance in the Rehabilitation Phase after ACL Reconstruction

Anterior cruciate ligament (ACL) reconstruction requires comprehensive rehabilitation to restore neuromuscular function and minimize reinjury risk. Quantitative assessment is essential for evaluating muscle recoveryand guiding return-to-activity decisions. This study aimed to assess isokinetic strength of the quadriceps, hamstrings, adductors, and abductors during the rehabilitation phase following ACL reconstruction.Methods:Eighty-five patients who underwent ACL reconstruction were evaluated using the Easy Torque isokinetic device. Peak torque and relative strength (N/kg) were measured bilaterally for key lower limb muscles. Subgroup analyses were conducted based on sex and athletic background to explore differences in muscle performance and recovery patterns.;Results:Isokinetic testing revealed no significant strength asymmetries between the operated and non-operated limbs for quadriceps and hamstrings, indicating effective bilateral recovery. While male and athletic participants exhibited higher absolute and relative strength values (p < 0.05), recovery rates were consistent across subgroups. Adductor and abductor strength also showed post-rehabilitation symmetry and robustness, supporting their relevance in functional assessment.;Conclusions: The findings support the use of isokinetic testing as a reliable tool for evaluating post-ACL muscle recovery. Standardized rehabilitation protocols effectively restored muscle symmetry across patient profiles, underscoring the value of comprehensive, multi-muscle assessment in return-to-sport decision-making.