Bilateral symmetry indices

The formula

Kineos uses the symmetry index of Robinson et al. for paired girths and for left/right ROM. Ten percent is a conventional clinical flag, not a diagnostic cut. Limb dominance in volleyball and throwing sports routinely sits at 4–8% without pathology.

Post-ACLR envelopes (see Elias Voss in the roster) often exceed 12–15% at the thigh and calf at 6–9 months. Re-test the same landmark, same tension, same clinician. ISAK intra-tester TEM matters more than a single SI%.

Kinematics versus anthropometry

A symmetrical squat can hide a force asymmetry. A girth deficit can exist with symmetrical angles because the athlete shifts work to the intact hip. Always read Z25 next to a unilateral hop or isometric strength test before you write the prescription.