I did it about the normal distance between the legs when the chick is standing typically and then a tiny bit extra. So, in my poult, it was maybe 1 1/2 inches or so. I had my roommate hold him and then I tape the legs roughly so they were set straight and then added a little give. The one thing that freaked me out a little bit is that he cannot get up off his back with his legs hobbled (I know, duh, right). So when he was learning, he kept tipping over on his back and couldn't get back up and it broke my heart. I just set him upright every time I saw that happened and he learned to walk by himself in about a day. Still can't get up off his back, but I think we will once I take the tape off.
