Originally Posted by Walrus

Geez. Biting a dog back won't teach them much other than to be scared of you. This would be considered inhumane by most dog trainers. Did you tell your trainer you did this?

One needs to practice bite inhibition when their puppy is young. You do this by practicing play biting. You play with your dog and when the pup bites too hard, you yell "Ouch!" They learn bite inhibition this way.