As a parent, have you observed your child’s legs and walking gait? Have you noticed that your child’s legs are not straight and he/she walks with an inward or outward gait? If so, this is often referred to as inversion or ectropion of the knee. There are many reasons for this, including rickets, calcium deficiency, genetics, early toddler, use of walkers, etc. There are also a few cases caused by trauma, inflammation, tumors or congenital epiphyseal dysplasia, which can occur unilaterally or bilaterally (unilateral onset is rare). Under normal circumstances, both lower limbs of children should be in contact with each other when the patella is in a straight standing position and the two knees and two inner ankles (inner ankle bones) are facing forward. If the two knees are not in contact with each other and there is a distance between them when the two inner ankles are together, the knee is pronated; if the two knees are not in contact with each other and there is a distance between them when the two knees are together, the knee is pronated. X-leg = Knee valgus Knee valgus is also called “X” leg, if it is unilateral, it is called “K” leg, the main manifestations are walking awkwardly, walking with both knees colliding with each other, easy to fall, toes inward; lying down, lower limbs straight, patella to the top, when both knees are together The greater the distance, the heavier the valgus. O-leg = inversion of the knee Inversion of the knee, also known as “O” leg, is mainly manifested by outward bending of the lower limbs, wide distance between the knees, walking wobbly, and inward deviation of the toes; in the lying position, the lower limbs are straight, the patella is directly above, when the bilateral inner ankles are together, the distance between the knees exists, the greater the distance, the heavier the inversion. If your child has the above symptoms, early examination should be performed to clarify the cause and degree of deformity for early treatment. Normal children have mild inversion of the knees (knee spacing <2 cm) from birth to 1 year of age, and then the lower extremities straighten out at the age of 1.5 years, which is a physiological inversion of the knees and does not require treatment. This is a physiological knee valgus and generally does not require treatment. The following treatment methods are commonly used: 1. Orthopedic shoes + orthopedic insoles treatment: The slope difference between the medial and lateral sides of the soles of Fulcrum orthopedic shoes allows the force line to the knee joint to be broken down into an inward or outward growth force to change the negative force line when walking, so that the deformity can be gradually corrected. 2. Brace treatment: The three-point correction theory of braces is used for treatment, and special orthopedic braces are customized according to the patient's specific condition and worn at night. Note that special brace makers are required, but the quality and effect of the brace varies greatly due to the difference in the level of the maker. When the brace is worn, the legs have to be kept in a constant state of tightness and cannot be curled and moved, so the compliance of the child is poor.