Try one--on yourself. Seriously...take a normal choke style collar, put it around your thigh and pull it like you would with a dog on a leash. It hurts like hell and you will have a bruise where the collar crosses. Then do the same thing with a prong collar, like the one pictured in this thread. Equal pressure all the way around, no pinching, no bruising.

Yes, I have tried it on myself. I don't use choke collars anymore. I do have a prong collar or two around the house. Most of the time I want my dogs to pull so I don't bother with any kind of training to stop it, but occasionally when taking a 140 pound malamute to the vet, the prong collar has been handy.