In addition, the design principle of flat foot insole is wrong, and the mechanical structure of arch is not clear.
The arch structure composed of upper and lower parts can be vividly compared to the structure of bow and arrow. The upper part is like the back of a bow, and the lower part is like a bowstring.
Plantar aponeurosis is an important structure to maintain the arch of the foot. If the arch string is relaxed, the height of the arch will inevitably decrease. The bow should have a bowstring, and the bowstring of the bow is plantar fascia (plantar aponeurosis), but the flat foot pad just ignores the structure of the "bow" and regards it as a "bow", but applying external force to the plantar aponeurosis from below will further relax the plantar fascia (plantar aponeurosis) and aggravate the flat foot. The looser the plantar aponeurosis, the lower the arch height and the more serious the flatfoot is.
Negative heel shoes with high front and low back can shift the center of gravity to the heel, reduce the pressure on the forefoot, and have a corrective effect on postural flat feet. The effect on congenital and traumatic flatfoot is unknown, but it can relieve pain, control development and improve quality of life.
You can experience it yourself: barefoot or wearing flat shoes at home, stepping on a book about 20 mm thick correctly, do you feel whether the symptoms are alleviated? Or wear flat shoes, pay attention to walking with heels, and experience whether the symptoms are alleviated and whether you can walk more.