ABSTRACT
Children commonly present with either bow legs or knock knees. It is important to differentiate between the common physiological forms and rarer pathological forms. The term genu varum or genu valgum is used if the femoro-tibial angle is more than 2 standard deviations (SD) above or below the mean for a particular age. Lateral tibial bowing is common in early infancy (10-15° is normal up to the age of 1 year). Normally the limb is straight by the age of 2. Physiological knock knee becomes maximal between 3 and 4 years of age (greater in girls than boys) and the normal valgus angle (approximately 5°) is established by the age of 7 or 8. There are familial and racial variations.
