W - Sitting

This week I've been learning about a new problem I didn't even know we had.
It's called W-sitting.
Sounds a bit odd, but I shall explain. When an adult has to sit on the floor (after all the grumbles and complaints about there being no available chairs and how hard surfaces always give them pins and needles) they will generally either sit with feet and knees together tucked under them or with both legs to one side. Some of the more flexible will sit cross legged in a school assembly style.
W-sitting means extending each leg out both sides and bending the knees so from above they're making a w shape. It's quite common in children who are learning to sit and many tots will use it as a half way point from sitting to crawling. It's also very stable as it needs less muscles to hold the upright position.
That's the main problem with it. Children who w-sit a lot don't develop as good core muscles as others and it puts the wrong sort of strain on leg muscles and joints. It can lead to walking with turned in toes and flexibility issues in later life.
Joseph does this a lot. I don't think it's a stability thing for him, his balance is very good. I think it's just that he wants to play with something on the floor in front of him and doesn't want his feet to get in the way. At only eighteen months I don't think he's been doing it long enough to cause any real trouble but I'm going to start trying to persuade him out of it from now on so that we can try to avoid any possible future problems.
The problem is how. He's not that persuadable a boy, he didn't want the sauce with his pasta tonight for no obvious reason and nothing I could do would persuade him otherwise. When he wants something he really wants it and is very rarely fobbed off with something else. When he's got something he wants that you'd rather he didn't then you're in for tears and tantrums and possibly having to give him something else he really wants but also shouldn't really have as a bribe to let the first thing go. Then you  begin the cycle again.
As far as his sitting habits go, over the last two days I've been straightening out his legs and pointing them forwards whenever I see him sit wrongly. Sometimes it works and he carries on sitting in a better position and sometimes he gives me a funny look and quickly settles back into a w shape.
However, there is one ray of hope. He likes to climb on my sit-kneel chair and it on it backwards to watch Timmy Time or Chuggington. Andy pointed out this evening that it was rather effective at stopping him sitting badly. Now all I have to do is stop him using it as a climbing frame!