To those wondering how the kid got marks on his back and legs:
Growing up, my granny used switches on us, or belts. We were to stand there and take our licks while she whipped us and explained what we did wrong and why it was wrong.
Maybe I was a weird child, but I just took the licks and listened to what she said. I know, that while I didn't get spanked/whipped much in my childhood, when I did I deserved it since I was being a hardheaded asshole and not listening when being punished in other ways.
I know my little brother once tried to fall down to not get whipped and got hit on the back a few times while doing so and it left marks. It wasn't intentional, but it happened. He also had a bad habit of wanting to put his hands back there to try and stop the switch. He'd end up with marks there too. I did it once or twice myself until I learned not to move and just accept the punishment, listen to the reasons I was punished, and learn from it.
Edit: That said, there is a difference between my granny/mom spanking/whipping me and Adrian Peterson doing it. Less so than my dad doing it, but there is still a difference.
Edit 2: Just seen where all the injuries were. Looks like he went overboard and the switch wrapped around and got him in the middle of it too. There is a line with spanking, and that crossed it.