Physiologic Genu Varum
In most children under 2 years old, bowing of the legs is simply a normal variation in leg appearance. Doctors refer to this type of bowing as physiologic genu varum.
In children with physiologic genu varum, the bowing begins to slowly improve at approximately 18 months of age and continues as the child grows. By ages 3 to 4, the bowing has corrected and the legs typically have a normal appearance.