Proper Leash Behavior is one of the first things we teach our dog training clients. It's not just about being able to walk the dog on a loose leash. It's also about being the one who gives direction.
As we explain in our dog training sessions, with dogs, it's 98% body language. So when you allow your dog to drag you behind him, while he pulls you on the leash, you are communicating that s/he is in charge on the walk. This can easily turn into reactive and protective behavior, such as lunging at other people or dogs, barking etc.
When you walk your dog next to you, or have him/her behind you, you communicate that you are in charge of the situation, and you will see far less bad leash behaviors as a result.
The walk starts inside your home
Each time you get ready to take your dog out for a walk, you communicate how you want your dog to behave. Make sure that your walk starts inside the home with a calm dog, that pays attention to you.
Once you go outside, smells and distractions are going to take your dog's attention - the video below will show you two (2) ways to get your dog to walk calmly by your side: