dt2 is a climber. he's only 10mo but can climb the side of the bath/radiator/his cot. he can't keep still even when bf. and in his ikea high chair he can go from sitting to standing in under 2 seconds even though we wedge him in with the inflatable cushion and use the lap strap, perhaps because we can't struggle to get the lap belt to stay tight. any tips? ds1 used this chair without problems, dt1 is fine in hers, but I'm at a loss with dt2. currently it's just not safe as my attention is already divided with dt1.
Have you got the belts through the wee plastic things the right way IYKWIM? if they are threaded through correctly it is quite difficult to get any slide on them at all - might be worth a second look at the instructions?
If you had to, you could always use a soldering iron / drill to add a couple more holes to the high chair body. Take child out first
I have the ikea highchair and have attached a harness like this
It comes with two bits that you can thread through the slits but the has a plastic adjustor thingy that stays on the outside of the seat to anchor them. Then you just attatch the harness to those bits and houdini is tied down!