Dog training has seen many changes in recent years. 30 years ago harsh training methods were the norm. Dogs were subject to choke chain and prong collars, with severe leash “corrections”. The mainstream of dog trainers considered that you had to give harsh pops on the leash to make the dog “respect” you, and therefore would be obedient.
Then several studies of the behavior of captive wolves were the driving force in dog training. This resulted in the theory that wolves and by association dogs live in packs and are dominated by the alpha dog. So trainings introduced the ruff shake (taking a dog by the scruff of the neck and lifting them up and shaking them) sometimes called Scruffing. And also the Alpha roll over. This involves hold a dog down by its neck until it submits.
Unfortunately there are still many so call “dog trainers” and “animal behaviorists” still used these methods.
Enlightened trainers now use humane methods with the premise that you reward the positive and ignore behavior that is not wanted. Training this way will make you think and try and get into the dogs head to find out what motivates the dog. once you know what motivates your dog you can use that to shape behavior.
If you are considering a trainer for your dog make sure that only positive methods are used.
In classes that I run the dogs are virtually free to do what they want, and I teach you to make your dog want to do what you want the dog to do.