Abstract:Objective To determine the effect of limb dominance on landing biomechanics and lower limb functional outcomes in patients with anterior cruciate ligament (ACL) reconstruction (ACLR). Methods Forty-nine participants were recruited and divided into the ACLR on dominant limb (ACLR-D) group, ACLR on nondominant limb (ACLR-ND) group and healthy control group. Single-leg jump landing, knee isometric muscle strength, Y balance, and single-leg hop for distance tests were performed on both limbs of all participants. Kinematics and kinetics data during the single-leg jump landing were collected by an infrared motion capture system and a force platform, and knee joint muscle strength was collected using the IsoMed2000 isokinetic muscle strength testing system. Two-way mixed-design ANOVAs were used to observe the effects of limb and group on the outcomes of each test. Results The non-surgical limbs had greater knee valgus (3.8±1.8°vs 1.7±1.3°), knee external rotation angles (4.8±2.3°vs 1.2±1.8°) and knee valgus moments (0.11±0.18 Nm/kg vs 0.08±0.22 Nm/kg) in single-leg jump landing in the ACLR-D group compared with the ACLR-ND group, and the bilateral knee flexion angles were significantly smaller in the ACLR-D group than in the control group (non-surgical limb: 12.7±6.1°vs 17.2±9.0°, surgical limb: 11.4±7.3°vs 18.0±6.5°). There were no differences in knee muscle strength, Y-balance composite scores and single-leg hop distance between ACLR-D and ACLR-ND groups, but the Y balance scores in ACLR-ND group were smaller than those in the control group (non-surgical limb: 92.8±8.5% vs 97.8±6.6%, surgical limb: 89.9±4.8% vs 98.1±6.3%). Conclusions Limb dominance has no effect on knee muscle strength, dynamic postural control, and single-leg hop function in ACLR patients. The non-surgical limbs of ACLR-D patients are at a higher risk of ACL injury due to the presence of more abnormal landing movement patterns.