This may be necessary if you have an aggressive dog or a dog who has lack of impulse control or reactivity.
When dogs become overstimulated or whenever they start making bad decisions – its triggered by their brain. A signal telling them to initiate a process that results in them doing things that make you want to pull your hair out. Whether its destructive to your property or your relationship with them like when they bite you or chew up something important or lunge and growl at other people or dogs.
If we can interrupt the thought process or learn to see the warning signs right before they do the negative behavior and give them a correction then we can shock their brain and snap them out of that thought, out of that place mentally.
Such as popping the leash toward you (leash pressure) right before your dog is about to bark at something or just before he sees something and tries to pull.
This is effectively shocking him out of that state of mind and then rewarding his calm nature, dogs only learn when they are in a calm submissive state.