Many parents bring their children to the hospital to consult or solve the problem of their child’s “inward” and “outward” walking posture. Many parents bring their children to the hospital for consultation or to solve the problem of their child’s “inward” or “outward” walking. They always feel that their child is different from other children and has an unattractive walking posture. They are worried about the impact on their child’s growth and development and want to solve the problem early so as not to miss the best time for treatment. When walking, the long axis of the foot and the forward direction of the pace have an angle, called the forward angle of the foot, which is usually mildly externally rotated, about 5 to 10 degrees. If the angle is less than this, it is called “inward”, and if it is greater than this, it is called “outward”. The vast majority of these deformities are normal variations and can gradually disappear. However, parents are concerned, especially if they can recall a past relative who had a similar deformity treated with a splint or orthotic. The problem of “inward” or “outward” walking is actually a rotational deformity of the lower limbs. What is the axis of rotation of the lower limb? The problem of “inward” or “outward” rotation of the lower limb is known as abnormal internal or external rotation of the lower limb during walking. The angle of advancement of the foot is the general effect of the rotation of the lower extremity, and the analysis of the cause of the increased external or internal rotation can help to identify the segment where the lesion occurs. The rotational alignment of the lower extremity includes the evaluation of walking (foot advancement) p lateral edge of the foot (which is internalized during metatarsal adduction) p leg-foot angle (tibial rotation) and hip range of motion, and we also need to consider the age of the child and the characteristics of the growth period. The rotational alignment of the lower extremities changes very significantly during the growth of the child. In general, the shaping effect of the uterus on the fetus causes contracture of the soft tissues of the lateral hip joint and internal rotation of the tibia and foot. As the soft tissue contracture of the hip disappears, the anteversion angle of the femur largely determines the internal rotation of the hip. The anteversion of the femur is approximately 30 degrees at birth and decreases to about 10 degrees at maturity. Similarly, the tibia is extremely internally rotated at birth, but as it matures, it gradually rotates outward, changing from an internally rotated 5-degree position to an externally rotated 10-degree position by the age of 8 years. Although there is a great deal of individual variation, it is important to understand these general patterns in the course of following the natural history of the vast majority of deformities. “How does “internal” or “external” brachiation occur? Rotational deformity of the lower limbs can occur in one anatomical segment or as a general effect of several anatomical segments. A thorough evaluation of the rotational deformity by physical examination and exclusion of more serious diseases (e.g. spastic paralysis, hip dysplasia, slipped femoral epiphysis, etc.) may require surgical treatment in a few cases where the deformity is severe or persistent. Rotational deformities of the lower extremities may consist of: 1) abnormal internal or external rotation of the femur; 2) abnormal internal or external rotation of the tibia; and 3) deformities of the foot and ankle. Very commonly, metatarsal adduction and other deformities of the foot can cause an internal “figure of eight”. Because the deformity of the foot can be more obvious before walking, it manifests earlier than the deformity of the femur and tibia. What to do if you have an “internal” or “external” deformity It is important to consult a specialist at the earliest possible time for a clear diagnosis. Neurological disorders, skeletal dysplasia, joint and ligament laxity, and metabolic disorders should be considered. Rotational deformities may occur in more than one segment, perhaps aggravated or compensated for by other deformities. Rotational deformities are a dynamic process and require periodic follow-up in order to evaluate the child and the progression of the deformity. If there is a unilateral onset p a history of progression p a deformity that can cause function-related symptoms p pain p asymmetry and progression that does not occur as expected, there is a high clinical suspicion that other diseases may be present. As a parent, it is important to communicate and cooperate with the physician. Until the diagnosis is clear, the best management of “internal” or “external” deformity is observation. Current research suggests that rotational deformities rarely require treatment and usually resolve on their own, but only those persistent deformities that do not resolve with growth and p cause functional and cosmetic concerns will require further investigation. When treatment is indeed needed, the only way to correct it is surgically. There are no reports showing definitive results for treatments such as braces p orthopedic shoes for rotational deformities of the tibia and femur, and these methods even cause discomfort to the child and interfere with daily life. It was previously thought that surgical correction of the forward rotation of the femur was intended to prevent early arthrosis of the joint due to abnormal stresses, but this has not been proven. The indications for surgical treatment of a persistently progressive and worsening anterior femoral rotation deformity are age older than 8 years and the resulting functional impairment or significant aesthetic impact. Rotational abnormalities of the tibia have a tendency to disappear spontaneously in the majority of the population, but if functional (e.g., knee pain, etc.) or aesthetic problems are present on an individual basis, surgery should be postponed until after 8 years of age.