During World War II, in order to improve the speed and time of soldiers marching, Germany studied and developed different types of feet. After the war, more and more attention was paid to this research. 1948, Romanian George Alznner went to west Germany to study plastic surgery, and then spent four years studying physiology and put forward the famous ehrlich effect. The so-called ehrlich effect is a principle that can correct the foot shape and straighten the body posture. Arch orthosis will train foot muscles and correct abnormal foot shape.