Why they work
CLOTHOID HEEL: The mathematically optimized heel and midfoot shape creates the smoothest possible transition affecting the Achilles, plantar fascia, shins, and hamstring tendons.
REVERSE DENSITY RATIO: Most people think that heel stability protects the knees from damaging torque. However, it is the forefoot that controls sideways knee torque. A softer heel/firmer forefoot reduces the potentially damaging stress.
HEEL CUSHIONING: Heel cushioning protects the back and knees from vertical impact stress. But bigger stack height is not better, because sole thickness increases rotational stress that can lead to damage.