The act of holding a dog down forcibly as a correction is generally called the "dominance down." It is inappropriate, ethologically absurd, and completely counterproductive when interacting with dogs. Fear doesn’t equal obedience, it just equals fear. I would bet everything I own that what Sophie’s dad did didn’t cause her to be any more obedient when put in that same situation again. It did cause her to distrust him and fear him. These are two states of mind that generally cause disobedience, not obedience. The best trainers train their dogs to be obedient without ever attempting this move. If you just won’t give up on the idea that your dog should submit to you, why don’t you just teach your dog to lie down on his side, then when you want to show him that he should be submissive, you can just ask for it. You can use a treat to lure him into the down position, and when he can reliably lie down on cue, you can start to use the treat to lure his head back toward his shoulder. If you want to show your dog that you are more powerful, intelligent, and dominant, while also teaching him to be obedient, get a handful of treats, then use the treat to lure him into the down position.