If you notice your child’s legs curve outward at the knees or that the knees touch but the ankles are apart, your first reaction might be to worry.¹

The good news is that knock knees and bow legs are rarely a cause for concern. However, in rare cases, knock knees and bowlegs can signal a more serious condition.¹

What are Bow Legs?

Bow legs is the term used to describe an outward curving of the legs. When a child with bow legs stands with their feet and ankles together, their knees stay apart.²

Most children have some bowing of their legs when they start to walk. Their legs gradually straighten out, usually by the time they reach 3 years old and may be followed by a period with knock knees.²

What are Knock Knees?

Knock knees is the term used to describe a large distance between the ankles when the knees are touching.²

Knock knees are common in children aged 3 to 5 years. In most children, as they grow, their legs gradually straighten and are usually in a normal position by the time they are 8 to 9 years old.²

What can affect how bow legs and knock knees look?

Toddlers learning to walk often have their feet further apart for support. This can also make the legs appear more bowed.³

If your child is above a healthy weight, they are more likely to look knocked kneed.³

Children with loose ligaments stretch their knee joints. This can often make their knee shape appear worse.³

When should a child be assessed by a pediatric orthopedic specialist?²

• Your child’s bow legs or knock knees are severe
• Bow legs persist after 3 years of age
• Knock knees worsen after 8 years of age
• Only one leg is affected
• Your child has pain or a limp
• Your child is unusually short for their age

How do doctors evaluate bow legs and knock knees in children?

The main way doctors diagnose bowlegs or knock-knees is through a physical exam. In addition, X-rays may be taken when needed to get more information about the knee joint.⁴

Do bow legs and knock knees need treatment?

• Most children with bow legs or knock knees do not require treatment and these will correct by themselves over time.²
• Exercises, splints or special shoes are not recommended.²
• When knock knees or bowlegs happen due to rickets, treatment includes adding vitamin D and calcium to the diet or seeing an endocrinologist if a genetic condition causes the disease.¹
• Surgical options are available for some older children after age 10 in some cases.¹

Finally

Although you may be concerned about the shape of your child’s legs, a slight degree of bowing or knocking is normal. That said, if your child has severe knock-knees or bowlegs, it’s a good idea for a pediatric orthopedist to take a look.⁴

Frequently asked questions

Are bow legs and knock knees normal in children?

Yes, bow legs and knock knees are a normal part of a child’s growth and these cases will correct by themselves over time.²

At what age should bow legs and knock knees disappear?

All children are born with bow-legs and these are usually present until about the age of 2. After this they become knock-kneed. The degree of knock-knee is most obvious between ages of 3 to 4. The legs then gradually straighten reaching an adult shape by the age of 10 to 12.³

When do bow legs or knock knees need treatment or surgery?

The doctor might recommend seeing an orthopedic surgeon if:¹

• Legs don’t straighten on their own
• The knee on one side turns in more than on the other side
• Your child has a limp, pain, weakness, or trouble running

Surgical options are available for some older children after age 10 to address these symptoms.

When knock knees or bowlegs happen due to rickets, treatment includes adding vitamin D and calcium to the diet or seeing an endocrinologist if a genetic condition causes the disease.

References

1. Scottish Rite for Children (n.d.) Knock knees and bowlegs: Should you be concerned? (Accessed: 21 September 2026).
2. University Hospitals of Leicester NHS Trust (2026) Bow legs and knock knees in children. (Accessed: 21 September 2026).
3. NHS inform (n.d.) Bow legs and knock knees in children and young people. (Accessed: 21 September 2026).
4. UCSF Benioff Children’s Hospitals (n.d.) Bow legs and knock knees. (Accessed: 21 September 2026).