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

Abstract

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

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

Study design: Observational cross-sectional study.

Level of evidence: Level 3.

Methods: 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%.

Results: 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.

Conclusion: 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.

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