The Influence of Limb Dominance on Performance-Based Outcomes After ACL Reconstruction

Considering limb dominance (LD) may be valuable when utilizing limb symmetry index (LSI) when assessing patients after anterior cruciate ligament reconstruction (ACLR).

Patients will have better performance-based outcomes when index ACLR occurred on the dominant limb (DL) compared with the nondominant limb (NDL).

Observational cross-sectional study.

Level 3.

A total of 279 patients (49.1% female, 20.83 ± 5.23 years; 48% DL surgery) completed a laboratory visit (7.65 ± 1.65 months post-ACLR) assessing LD influence on knee extension and flexion peak torque, center of pressure (COP) distance and velocity, and hop performance. LD was defined as the preferred limb to kick a soccer ball. LSI variables were converted to indicator variables and categorized as "Pass" or "Fail" based on LSI ≥ 90%.

Patient LD and isometric knee extension LSI Pass status were significantly associated (χ² = 10.09; P = 0.001). No additional associations were found between LD and other LSI Pass status variables (P > 0.05). Patients with DL ACLR demonstrated more symmetric knee extension peak torque (P < 0.001, d = 0.42) and 6-meter hop (P = 0.02, d = 0.25) outcomes; NDL was more symmetric during COP distance tests (P = 0.03, d = 0.40). No differences were observed between LD and raw strength or balance measures (P > 0.05). Patients with ACLR on their NDL jumped farther on their contralateral limb for triple-hop (P = 0.03, d = 0.23) but not single-hop (P > 0.05) distance.

LD appears to influence isometric knee LSI in patients post-ACLR; patients with surgery on their DL achieved higher symmetry and a greater rate of LSI Pass success for knee extension strength.

Addressing differences in recovery patterns between DL and NDL may improve rehabilitation precision and guide return-to-activity timelines after ACLR.