What are bowlegs and knock knees?

Bowlegs is the term for legs that bow outwards at the knees. Your child’s knees do not touch when he stands with his feet together. Bowlegs are very easy to see at 12 to 18 months, when your child starts to stand and walk.

Knock knees is the term for lower legs that angle out from the knees. Your child’s ankles do not touch when he stands with his knees touching. Knock knees usually are noticed between the ages of 3 and 6.

What is the cause?

A baby’s legs are folded inside the mother’s uterus before birth. Most babies are bowlegged at first, but grow out of it by the age of 2. Bowlegs may also be caused by:

• Problems with bone development or broken bones that do not heal properly
• Rickets, which is a disease caused by a lack of vitamin D

Most children grow out of being bowlegged by becoming knock kneed between age 3 and 5 years of age. This is the most common cause of knock knees. For children over the age of 6, knock knees may be caused by a bone problem, or by obesity.

How is it diagnosed?

Your healthcare provider will ask about your child’s symptoms and medical history and examine your child. Your child may have X-rays if he is old enough to have outgrown bowlegs or knock knees.

How is it treated?

Most children with bowlegs don’t need treatment. Standing and walking helps the legs straighten.

Legs that look knock kneed usually start to straighten out by age 5 or 6 as your child grows. The legs will typically look normal by age 7 or 8.

If your child’s bowlegs or knock knees are caused by obesity, a bone problem, or lack of vitamin D, treating the condition will help. Your healthcare provider may refer your child to a bone specialist. Rarely, children may need braces, special shoes, or surgery to help straighten the legs.

How can I take care of my child?

Follow the full course of treatment prescribed by your healthcare provider. Ask your provider:

• If there are activities your child should avoid and when he can return to his normal activities
• How to take care of your child at home
• What symptoms or problems you should watch for and what to do if your child has them

Make sure you know when your child should come back for a checkup. Keep all appointments for provider visits or tests.