Q. Now that my baby is four months old and can put weight on her legs, she likes to stand up on my lap while I sit and hold her up. Is that OK? My parents say that it will make her legs bowed.
It is common developmental milestone that babies begin to bear weight on their legs by about 2 to 5 months. They won't be able to actually stand up while holding on to things until they are 6 to 9 months old, but at this age, they can often put weight on their legs while you support their body.
Does standing up at this age lead to bowed legs?
No. Most infants have bowed legs because of the way that they were positioned in their mother's uterus before they were born. This bowed appearance is especially noticeable once the child is walking and typically goes away when they are about 15 to 24 months old.
In fact, their bowed legs may seem to over correct so children seem almost knock-kneed by the time they are 3 or 4 years old. This too usually goes away on its own by the time a child is 5 to 8 years old, when your child's legs will finally appear straight.
Bowlegs
Having bowlegs (genu varum) is not always normal though.
None of these conditions are very common, but they do include:
- tibia vara (Blount's disease), in which the tibia, one of the lower leg bones isn't growing correctly
- Vitamin D deficiency (rickets)
- skeletal dysplasias, in which bones don't form normally, and usually include other issues, such as short stature, in addition to bowed legs
Instead of slowly improving, as most infants with normal or physiological bowing do, infants who have a medical condition causing their bowed legs will get worse. Still, letting your baby bear weight on her legs will not cause the bowing.
Talk to your pediatrician if your think your baby's bowed legs are a problem.
Sources: Behrman: Nelson Textbook of Pediatrics, 17th ed.
