One of the greatest milestones achieved during a baby’s first year of life is sitting. This is an enormous progression towards independence for the child and the parent. Sitting is typically learned around 5 months of age through “prop sitting,” where the child is placed in a seated position with their hands down in front to assist with balance. At 5 months, babies do not have the postural control (balance) to sit without some assistance. Between 6 and 8 months of age, babies can sustain a seated position independently.
There are many varieties of seated positions:
Long sitting with feet directly out in front
Ring sitting with legs in a ring position and feet either touching or slightly apart
Tailor sitting or Indian style sitting
V-sitting with legs straight like a V
Side sitting when knees are bent and both feet are pointed to the same direction
W-sitting when both feet are behind and legs look like a W
Throughout a baby’s normal development, each of these sitting postures is normal. You will frequently see your child transition in and out of these sitting postures frequently as they lead up to independent walking.
A Baby W-Sitting
Although I just stated that all of these sitting postures are normal, I want to stress the importance of children not excessively W-sitting. W-sitting does not pose a long term concern if your child transitions in and out of the position smoothly and efficiently, and does not maintain the position during periods of seated play. W-sitting regularly can cause secondary hip and knee problems during walking, seen through excessive inward feet because of the position of their legs and hips.
Not every child who W-sits will acquire a skeletal or muscular problem; however, it is extremely difficult to change these impairments once they begin. W-sitting limits the amount of rotation that is typical during play, creating a pattern that does not utilize good core strength. To prevent any negative hip or knee changes and the likelihood of core strength concerns, encourage your child to sit with “feet in front”.
By the time your child is 15 months old, you should rarely see your child in the W-sitting position. Children are very intelligent and the W-sitting position (if hip flexibility allows for it) is the easiest way to sit without using any core strength. It allows children to “lock out” at the pelvis and play in a seated position with the least amount of effort. Children that have lower tone and need to work harder to maintain a seated position choose to W-sit frequently.
If you notice your child W-sitting too frequently, encourage a feet forward seated position. You could also bring toys up to a taller surface so your child either has to sit and play on a chair or in standing to discourage the W-sitting position.
If you spend over a week with cueing and changing environment of play and you still notice constant W-sitting, an appropriate recommendation is to have your child evaluated by a pediatric physical therapist. The physical therapist will check the range of motion of the hips to make sure that your child has functional external hip rotation to allow for a comfortable tailor sitting. The physical therapist will also check to make sure that the core strength is appropriate to maintain a seated position with feet in front for functional play.