Visit any preschool classroom and you will probably hear the teacher correcting students who are “W-sitting” to sit criss-cross applesauce. While there are many opinions on w-sitting, most occupational therapists agree that it is something that should be addressed. Children typically choose this posture because it is more stable for them. W-sitting allows them to concentrate at the task at hand rather than trying to balance their little bodies as they attempt to rotate their trunks and reach for things on the floor. For those with a weak core, or turned in thighbones, this is a more comfortable option.
The downside of w-sitting is the stress that it inflicts on hip and knee joints - the tightness that develops often leads to walking “pigeon toed” which can later result in pain in the pelvis and back. Sitting this way may also delay development of the core muscles and postpone bilateral coordination. According to ‘The Inspired Tree House': "Every motor skill a child develops is a product of developing the milestone before. So, if a child has difficulty developing bilateral coordination, s/he may then demonstrate delays in skills such as developing hand dominance, skipping, throwing, kicking, etc."
For more information on w-sitting and how to help your child knock this habit check out these articles: