My 6 year old son has been torpedoed several times by Harley. Each time Harley was looking backward as he was running forward! I have been amazed at my son's resiliency. Each time he popped right back and dusted himself off.
Harley also torpedoed a tree once (again looking backward while running forward). Note to all Dobermans out there: I know you all have absolutely no fear, but trees are torpedo-proof. I thought I was going to have to bring Harley to the vet. However, after about 30 seconds of loud wailing and standing absolutely still (it felt like 10 minutes to me), he started to walk it off. Within 10 minutes, he was zooming around again. But nowhere near the trees (he's not a fool)!
I guess young fellas in all species have really soft bones and joints! I witnessed each one of these incidents and I don't think I would have been fully functional for days if I were on the receiving end.