Asymmetry in Recreational Athletes One Year After Anterior Cruciate Ligament Reconstruction: Comparison of Isokinetic Strength and Hop Test Performance

BACKGROUND AND PURPOSE: After anterior cruciate ligament (ACL) reconstruction, strength and performance asymmetries are widely considered relevant indicators for return to sport; however, the definition of acceptable asymmetry thresholds remains controversial. Here we compare the level of asymmetry in isokinetic knee extensor outcomes and vertical and horizontal single-leg hop tests performance one year after ACL reconstruction in recreational athletes. METHODS: Cross-sectional study. A total of 32 recreational athletes (females n = 13) one year after ACL reconstruction, with a mean age of 26.21 ± 7.95 years, were included. Peak torque, power, and total work were determined at 60°/s and 180°/s during isokinetic testing. Single-leg hop tests (drop jump and countermovement jump) and vertical hop test (triple hop test) were assessed. RESULTS: Significant differences were observed between limbs in all tests (p < 0.05). No differences in asymmetry were found between the isokinetic and vertical hop tests, with asymmetry values ranging between 13% and 18%. The horizontal hop test showed the lowest asymmetry (4%) and exhibited significant differences compared to all other tests (p < 0.05). DISCUSSION: Our results indicate that, one year after ACL reconstruction, recreational athletes often continue to exhibit inter-limb asymmetries in isokinetic strength and jump performance that exceed the commonly accepted 10% threshold, except for the horizontal single-leg hop.