Bow-legs occur when a child's legs curve outwards. This bowing develops while a baby is growing in the womb, when the bones are soft and flexible.

The bend in the legs may also cause a child to walk pigeon-toed, with the feet pointing inwards. A doctor can usually identify bow-legs by examining your child. X-rays are not always needed.

Some bowing of the legs is common in newborn babies and children up to two years of age. The legs naturally bow outwards and usually begin to straighten as a child grows.

Bowing may still be present up to the age of three years and it is then common for a child to develop knock-knees. A family history of bow-legs is also common.

What treatment is needed for bow-legs?

For most children, bow-legs correct themselves with normal growth and development.

If you are concerned about whether the bowing is improving, you may find it helpful to take photographs of your child's legs every six months to keep a record of any changes.

If the bowing becomes worse as your child gets older, or one leg becomes more affected than the other, you should seek medical advice.

In a small number of children, bowing may be caused by an underlying condition that requires treatment. Rarely, surgery may be needed to straighten severely bowed legs, particularly if there are associated knee problems.

What are knock-knees?

Knock-knees are often first noticed between the ages of three and five years. As with bow-legs, this is usually a normal stage of development.

By the age of seven years, the knees usually straighten naturally, although some children may not fully correct until adolescence. Many adults continue to have a mild degree of knock-knee.

Knock-knees may also be seen in children who are overweight.

What treatment is needed for knock-knees?

As with bow-legs, treatment is rarely needed because normal growth usually corrects the position of the knees.

If photographs taken every six months suggest that the knock-knees are becoming worse, or one leg is significantly more affected than the other, seek medical advice.

In very rare cases, if correction does not happen naturally, surgery may be required later on. This is uncommon.

The vast majority of children with bow-legs or knock-knees are developing normally and do not require treatment. In some circumstances, however, a healthcare professional may recommend orthotic braces, specialist footwear, casts or surgery if the condition worsens.

Normal development of leg position

• bowing of the legs is common under the age of three years
• knock-knees are common between the ages of three and five years
• most children's legs are generally straight by the age of seven years.

Knock-knees are not usually treated because children often grow out of the condition.

In some cases, specific exercises may help strengthen the muscles around the knee and improve stability. Your podiatrist, physiotherapist or consultant will advise whether exercises are appropriate for your child.

Bowing of the legs is common under the age of three years. 

Knock-knees are common between the ages of three and five years.

Most children's legs are generally straight by the age of seven years.