pulling

Question
How do I stop my dog (a 1 year old lab)from pulling when I walk him?  I have had a trainer and she advised me to use the gentle leader which works to a degree, but my dog still pulls and it doesn't take long until he breaks the gentle leader.  have a bad back and am afraid to walk him although I think we would both benefit from it.  Please help!

Answer
One gentle technique I like is to just stop when he pulls. He wants to go. If you move forward when the leash is slack, and stop when he pulls, he should quickly figure out the only way to get to go, is not to pull. This is about teaching him not to pull, not getting somewhere. The man that taught it to me said "If in a half hour you haven't made it out to the front walk, fine, you have taught him a lesson. Pulling the dog backwards is a good technique too.