The foot bones can be divided into three segments: hindfoot (talus and heel bone), midfoot (navicular bone, dice bone and three cuneiform bones), forefoot (metatarsal and toe bones), and these bones and their accessory ligaments form three arches namely medial longitudinal arch, lateral longitudinal arch and transverse arch. There are four layers of intrinsic muscles in the foot, including the first layer: the adductor, toe dorsiflexor, and little finger adductor muscles; the second layer: the metatarsal square and earthworm muscles; the third layer: the adductor flexor, muscle retractor, and little toe dorsiflexor muscles; and the fourth layer: the interosseous dorsalis muscle and interosseous plantaris muscle. These muscles are extensively connected to the metatarsal tendon membrane, the ligaments and tendons of the foot. These tissues form a powerful complex of dynamic and static structures. Although the foot muscles can perform the following movements such as abduction, adduction and flexion, their primary function is to support the arch of the foot during walking and running, supplementing the force of the long flexors against the flexors in the swing phase to maintain extension. Understanding the muscles and bones of the foot, let’s understand what deformities there are in the foot: There are many causes of foot deformities, such as congenital deformities of the bone, muscle atrophy or spasm, weight-bearing stress, ligament degeneration, bone hyperplasia, and wearing unsuitable shoes for a long time. Foot deformities are as follows: 1, exotropia: foot different degrees of rotation forward, exotropia, weight pressure on the medial longitudinal and transverse arches, and the arch downward collapse, the most serious for flat feet or structural rigid flat feet. 2, inversion of the foot: foot different degrees of rotation back, inversion, weight pressure on the lateral longitudinal arch, is to make the medial edge of the foot off the ground. 3, supination foot: the patient walks with the heel, the front part of the foot does not contact the ground. 4, horseshoe foot: walking with the metatarsal head, the heel does not touch the ground. 5, arch foot: too high arch of course, there are two kinds of deformities combined, such as supinated toe clubfoot, horseshoe clubfoot, horseshoe arch foot.