You could use foam hair rollers(Dollar Store)Cut to size with vet wrap on the outside. The rollers have a hole in the middle. Cut them length wise first then to the height you need on the leg. Wrap the outside with vet wrap. The foam will support the legs it won’t cut off circulation and it will be light enough that the chick can use its own muscles (build the muscles) when it walks. The rollers come in all sizes. They make tiny ones. That’s what I would try.
I just checked you can order them on line from Walmart.
Best wishes