In order to prevent the harsh jerking on your dog's collar when walking, make sure your leash arm is 'anchored', either by looping your thumb in your pants, keeping your hand in your pocket or ensuring your hand/arm remains fixed against your belly via an invisible hook :) If you want to make it very easy......use a hands free leash and never put your hands on it.

My default position is hand on my belly. I spend a lot of time with clients teaching them how to keep their hands from interfering with the leash. As long as your arm is able to 'float around" you are likely to pull back when your dog pulls forward. That engages the "Opposition Reflex" and works against you.
Once you remove the ability to tug on the leash, all of a sudden you have to figure out another way to get your dog's attention.