Dr. Rothbart measured the First Metatarsal Deficit (FMD) at the medial edge of the first metatarsal head. He discovered that providing a ground force under the first metatarsal and the big toe by inserting a wedge shape roughly 1/3 of the measured FMD, the average patient would experience an observed reduction in dynamic hyper-pronation of approx. 70% (as observed through a threadmill pressure analysis).
You know the rest of this story too - better body alignment and a more erect posture. Improved balance and athletic performance, reduced pain and excited, satisfied patients!