This is the first study to establish evidence-based diagnostic criteria for LE against an appropriate reference standard. The two thresholds with the highest sensitivity, as well as good specificity, for detection of mild LE were determined from a normative population, accounting for normal inter-limb variations as well as limb dominance. These findings support the adoption of a more liberal diagnostic threshold set at 2SD above the mean, instead of the previously suggested 3SD threshold. Open access: Yes View