Now that my kids are too big for high chairs, the weight of their dangling legs gets uncomfortable after a couple minutes. They try all sorts of things to get comfortable: pulling up their knees, twisting around to pull one leg up, trying to rest their feet on me and my wife, kicking anything within reach, etc.
And they're kids, of course, so it's natural for them to have more energy than they know what to do with. But still, I wanted to find some way to help them be a little more comfortable at the table and put more energy into eating their food and family conversation.
This cheap and easy addition to our dining room chairs prevents kids legs from dangling uncomfortably. It won't get all their wiggles out, but it will help them sit more comfortably... and now that our kids can sit more comfortably facing the table, they get less food in their laps and on the floor and we all enjoy meals more.
Another nice thing about this design is that the height of of the footrest is adjustable, so it will continue to work well as their legs grow longer.
If your kids are like mine, I strongly suggest letting them watch and play with the parts as you build this. Let them help, even if it's only to learn the names of the parts and hand them to you as you need them. They'll be super-curious and more eager to give it a try when it's done.