Parents to a 23 weeker here, now one year actual or 8 months adjusted.
He's still unable to sit up on his own, even though he's done so with help for many months now. Between his high chair, bath seat, wearable seat wedge, and his pram, it's safe to say he's had a LOT of practice at sitting. Yet he still just slumps to one side without support? I've started sitting him on his playmat with teddies wrapped around him while he plays, for however long he'll tolerate it, but now I'm thinking isn't that no different to all the other forms of assisted sitting? Are any of these things getting him to use those muscles? It seems like he takes the support for granted and so doesn't try, so we're not sure where to go from here.
Of course, if this is just something he'll do in his own time, that's completely okay too. We're just worrying this is our fault somehow.