You have a dog who just jumped on your friend. Worse yet, possibly your dog is also nipping at your friend's shirt, being really wild, and just having a big, out-of-control party with its front feet nicely planted on your friend's chest.
Our instinctive next move is pulling the dog away from the "victim". Literally grabbing the collar or leash, we pull our dog back, away from our friend. While we try to squeeze a sincere apology into this mess of a situation, we notice that our dog pulls even harder into our friend. So we have to add more strength to keep the dog from jumping up again!!!
Why is this?
1) What we think makes sense to do here is not at all what we need to do. Opposition reflex is at full force and makes the dog want to pull harder into what you try to pull against. And even if we managed to throw enough physical strength at this man-handled disaster,
2) we never addressed how the dog FEELS in that moment. The feeling being a giant party on the victim's chest or arm or sweater. In the moment of pulling the dog away and keeping him away, he is still attached to the victim in his mind!
In order to "break" this cycle, I usually suggest pulling UP on the collar or leash, very gently, and just enough so that the dog detaches from what it's grabbing. Once you settle your dog back down right in front of the victim, you make the dog do a meaningful behavior to redirect the feeling of 'party on sweater' to 'having fun with owner'. This is not easily done at first. Using the leash to block the unwanted choice of jumping up again while making yourself most valuable with meaningful behaviors your dog identifies with is the best ticket to these life skills.
If you had a leash on your dog when this happened, it technically should have never become a problem. The leash can and should be used as a tool to block the unwanted behavior of jumping in the first place, however, I will elaborate on this topic in a different post.