Bowed legs and knock-knees BOWED legs and knock-knees are common conditions in childhood. Most children will go through stages of having bowed legs and knock-knees as they grow. Bowed legs Bowing of the legs is where the legs bend outwards at the knees. Bowing of both legs is common in infants and children up to the age of two years. In fact, the majority of children have bowed legs at around 12 months of age. As children start to walk, the bowing generally corrects itself, and in most cases it has corrected by two years of age. Occasionally there may be causes of bowed legs other than a variation of normal growth and development. If the bowing seems to affect only one leg, if the child is not growing normally, if the child is older than three years, or if the bowing seems to be getting worse as the child gets older, the child should be seen by their doctor. Knock-knees Knock-knees are when the legs bend inwards at the knees. Knock-knees are common between the ages of two and seven years. In these ‘normal’ cases, the deformity is symmetrical (the same on both sides). With time, the legs will become straight as the child grows. A helpful way of assessing the problem is to measure the distance between the bones that stick out on the inside of the ankles. As the child grows, this distance should become less. Occasionally there is a medical cause for a child being knock-kneed. In cases where the deformity is not the same on both sides, or does not get better with time, or persists after the age of eight, the child should be seen by their doctor. Attempts to ‘cure’ knock-knees with splints, shoe inserts or exercises make no difference. Children with knock-knees who are older than eight years should be referred to a paediatric orthopaedic surgeon for an assessment. Sometimes a simple operation may be required to correct the deformity.