I hope you don't mind a bit of a different experience with this.
I am an ol cowboy who, for 40 years or more, taught babies to tie by tying them to the stoutest tree I could find. I used an innertube between the baby's lead rope and the tree to give some "give" to the setup. Worked for me for 40+ years.
Then about a year ago--maybe less--I had a youngster really freak out on me. She was tied via lead rope and innertube to an 8 x 8 post set 4 feet in the ground using a 50# bag of concrete. The day she freaked over it, she broke the lead rope, the halter, and pulled the post out of the ground. It is amazing how strong a baby can be. And she was so freaked that there was no way I could get close enough to her to release her. So everything broke and she flipped over, picked herself up and ran straight into her stall.
The incident changed her whole personality. She had been a sweet, easygoing youngster that you could handle all over -- and she turned into a mean, distrusting, kick/bite-you-first-and-ask-questions-later adult. Heaven help the person who startles her or crosses her. She will fight you to the death--hers or yours--it doesn't seem to matter which to her.
So I started all over with her. It has taken many months but she does finally trust me. Me. NOBODY else. A sensible person would probably put her down. I won't do that. I made this mess and it is up to me to fix it. And she cannot be tied. Not anywhere or with anything. She will kill herself to get free.
Oh, and one other detail: This perfectly formed youngster now has one foreleg that is 2" shorter than the other. We believe but cannot prove that this happened during the tie-out thing. When the halter/lead rope broke, she flipped over backwards and got up limping on that leg. The growth plates in that cannon fused and the leg stopped growing while the other leg continued to grow. We've been told the surgery to correct this will cost upwards of $10,000. For a mare no one can handle but me (and even I cannot handle the injured leg--although we are working on that). One result of all of this is that I taught everyone in the barn (including her) to ground tie.
I think if I were starting a baby today, I would teach the halter, leading, AND ground-tying before I ever tried tying that baby to anything solid. Because you never know what could happen when you tie them. I tied horses for all of my adult lifetime without a serious accident until this happened. Now I don't tie anybody.
Rusty