LSI uses the unaffected limb as a "patient-specific" normative control, accounting for individual differences in size, age, and baseline athletic ability.
LSI (%) = (Involved Limb Value / Uninvolved Limb Value) x 100
LSI (%) = (Uninvolved Limb Time / Involved Limb Time) x 100
LSI can be deceptively high if the healthy limb has also deconditioned during the recovery period. Always check absolute strength values against pre-injury or age-matched normative data.
Grindem H, et al.
Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction.
