Bow legs in children

All babies are born with bow legs but these gradually correct so that by the time the child is around three are to four years old when they tend to have knock knees.  Bow legs tend to be most pronounced at around 18 months of age.  In the vast majority of children there is no underlying problem and the child’s legs will change shape with growth.  In a very small number of children there may be a cause for bow legs rather than it being part of normal development.  Physiological bow legs (i.e not related to an underlying condition) are just part of normal development and almost never need treatment as they correct spontaneously.

There is no evidence that wearing different kinds of shoes or insoles will change the shape of your child’s legs. Nor will any physiotherapy or similar treatments.

What are the typical signs that may indicate an underlying problem:

  • bow legs that persist after age 2 1/2
  • if only one leg is affected
  • child has pain or a limp
  • child is unusually short for their age

When the bow legs are not part of development, the most well-known reason for a child having this type of problem is rickets which is due to vitamin D deficiency.  Blount’s disease is the next most common cause of bow legs but this is very rare and is caused by a growth disturbance of the bone just below the knee that leads to progressive bowing.  There are few other conditions which are also very rare.  If your child’s bow legs are outside of the normal range then your doctor may want to investigate for an underlying cause.  This may involve taking X-rays or doing some blood tests.  In some such situations treatment will be required.

Please note that these conditions are rare and the vast majority of children have bow legs as part of their normal growth and development.