In the past I have seen it noticed that my son sits in a w position, even therapy assistants bug my son to sit in a different position. At the time I thought it was just plain annoying, I honestly thought would you leave the kid alone! So whilst reading one of my new books Raising a Sensory Smart Child by Lindsey Biel, I come across this topic and this time I thought I should actually take an interest.
In case you are wondering what on earth I am going on about, this is what W sitting looks like. Lindsey discusses this in her book "When sitting, a child with low tone may always sit on the floor in a position that resembles a W, bearing weight equally through his bottom, legs, knees, ankles, and feet. This widens his base of support and frees up his arms for play. In this position, this trunk is inactive and he often slumps. While this is a very stable, secure position, it does not encourage the development of postural control." pg 200
The question is what to do about it. The issue with W sitting it can reveal other issues that can be at play such as low muscle tone, stiffness in the hips, instability in sitting which can all be linked to childhood disorders such as sensory processing disorder, also associated with children with autism, and in our case the issue of hyper-mobility of their joints.
From here I think it is important not be become a sitting sheriff and pester our children to sit properly or correctly. More importantly it is to teach them what to do and strengthen them to be able to do it. One issue that can arise is the fact that your child might not be ready developmentally (such as a baby or toddler) or your child's individual delays might slow, this is something that you as a parent and your OT if you have one should be deciding.
If you are thinking of doing something then this is where to start. I found a great article that gives some practical tips from Learning Links. What will assist your child to sit better are firstly building up their core strength through activities such as using a scooter board, swimming, standing on a balance board or sitting on a fit ball and as a parent modeling other ways to sit is helpful, encouraging different ways to sit in a non threatening manner will also help. What will be the challenge for some time is it is easier for your child to sit in the w position, so they will naturally resort to sitting this way. I would even bet that they don't even know why they sit this way. But as they get older it is even more important that they learn to sit in a different way. So here's to change.