About bow legs and knock knees in babies, children and teenagers
Bow legs are when the legs curve out at the knees.
Knock knees are when the legs curve in at the knees.
Both bow legs and knock knees happen when the bones in each thigh and leg line up differently while a child is growing.
Most children aged 18 months to 2 years have some bow-leggedness. Bow legs are sometimes more noticeable when children start to walk.
Knock knees often develop after bow legs. They’re common in children aged 3-5 years. Many children grow up to have slightly knocked knees.
Bow legs and knock knees are more common in children of above-average weight.
Bow legs and knock knees can be the result of other problems like rickets, which is a vitamin D deficiency. This is very rare.
Symptoms of bow legs and knock knees
If your child has bow legs, you’ll notice that their ankles touch but their knees are apart when they stand with their feet together.
If your child has knock knees, their knees touch but their ankles are apart when they stand with their feet together.
Medical help: when to get it for children with bow legs or knock knees
Here’s when to take your child to see your GP:
- Your child is over 2 years of age and has severe bow legs or knock knees.
- Your child has bow legs after 3 years of age.
- Your child has knock knees that get worse after 8 years of age.
- Only one of your child’s legs curves in or out.
- Your child has pain or a limp.
If you’re worried about your child’s legs, you can take photos of your child’s legs every 6 months to show your doctor how the legs are changing. Take a photo of your child standing with their knees facing forward.
Treatment for bow legs and knock knees
Most children with bow legs or knock knees don’t need treatment.
If your child has bow legs or knock knees, their legs will usually line up properly on their own. Bow legs usually line up by 3 years of age, and knock knees usually line up by 8 years of age.
In severe cases of knock knees, older children and teenagers might need surgery.
If your child’s bow legs or knock knees are caused by an underlying condition, that condition might need treatment.