Knock knees (Genu Valgum) describes the position when the knees come together and the lower legs angle outwards. This is a normal stage of growth. Children do not usually require treatment but occasionally may require further investigation if there are other concerns. A gap of 8 cm between the ankles is normal.
If the ankle intermalleolar distance is more than 8cm then a referral on to the orthopaedic service may be appropriate.
Bow legs are actually a normal part of a baby’s development. As the legs grow and develop from birth, they normally go through a period of being bowlegged. If the baby stands or lies with their feet together, there will be a space between the knees. This bowing is due to the forming of the legs while the baby is still in utero when the bones are soft and flexible. The bowing in the legs often causes the child to also walk in-toed. This period is from birth and can sometimes be present until 6 years of age. The bow legs usually straighten out with no treatment.
A gap between the knees of 6 cm is normal. If the knee intercondylar distance is more than 6cm then a referral on to the orthopaedic service may be appropriate. Information on these can be found on the NHS Choices website www.nhs.uk in the pregnancy and baby section under leg and foot problems in children.