What is it?
“W” sitting is when a child (or adult) sits in full bilateral hip internal rotation with full contact of bottom on ground, bent knees, and feet splayed out to the sides.
Why do children do it?
In this position, children are able to achieve a wider base of support which increases trunk and hip stability. This position requires less postural control and activation of the trunk musculature which can allow the child to concentrate on playing or a given task. The child can also easily transition from crawling and standing. This tends to be a position of comfort for children with poor core stability and children/adults with femoral anteversion (inward twisting of the thigh bone).
Why is it considered bad?
Many healthcare professionals believe that this type of sitting can lead to orthopedic conditions, delay development of postural control and stability, create weakness in the back, hips, and abdominals, stress muscles and joint capsules of hips, and possibly delay gross motor skills, coordination, and balance.
Other professionals believe that the reverse picture may be occurring. They believe children choose to sit in these positions due to underlying conditions such as femoral anteversion, low muscle tone, and muscle tightness.
What you can do?
Everything in moderation. If the child is transitioning in and out of different positions and occasionally chooses “W” sitting then this should not be concerning. But if the child is only sitting “W” style, then alternative positions should be utilized. In this instance, I urge you to encourage other positions like kneeling, ½ kneeling, long sitting, side sitting, cross legged (criss-cross applesauce), or a deep squat.