This is how the shape of baby’s legs changes The reason why baby’s little feet appear to walk in an inward and outward position is related to the shape of their legs: O-legged babies walk in an outward position, while X-legged babies walk in an inward position. During the growth and development of the baby’s legs, there is a change from O-legs to straight legs to X-legs, so the footprints left by the baby’s feet will also have three shapes: figure-eight, parallel arrangement and inner figure-eight. Generally speaking, from birth to adolescence, there is a physiological change in the line of force (axis) of the lower limbs of a healthy baby: in the neonatal period, there is an inversion of the knee of about 15 °; at about 18 months of age, as the baby learns to walk, the line of force of the lower limbs gradually becomes straighter; after toddlerhood, there is an outward turning of the knee of about 12 °; and in adolescence, there is an outward turning of the knee of about 4 ° to 6 °, just as that of an adult. This physiological phenomenon of angulation of the lower limbs can be corrected on its own as the baby grows and develops, and does not require treatment or restriction of activities, only observation. However, due to trauma, epiphyseal dysplasia, metabolic diseases and other reasons can cause pathologic angular deformity of the lower limbs, can not rely on the growth potential of young children to self-correct, and often need to support the treatment or surgical treatment. After understanding the developmental process of the baby’s legs, it is not difficult to understand the problem of the small feet of the internal eight, external eight. These problems are physiological, which means that they are a normal part of your baby’s growth and development, and mothers and fathers do not need to worry or be concerned about them. Does it need treatment? Do babies with O-legs and X-legs need treatment? Generally speaking, if the distance between the knee joints (knee spacing) in babies with O-legs or the distance between the ankle joints (ankle spacing) in babies with X-legs is not more than 5 centimeters, there is no need for special treatment, and observation is all that is needed. Above 5 centimeters, splinting may be recommended. Splinting is a common term for the specialized term “orthopedic brace”. For babies with knee or ankle spacing between 5cm and 10cm, splints only need to be worn at night, for about 4 hours to 6 hours every night. If it is more than 10 centimeters, the splint needs to be worn both during the day and at night. Splinting is not effective and even surgery is needed. I wish every little baby’s little feet a solid first step in life.