Walking, chain

I use one of four tools when I walk the different dogs. These four tools are a chain, a halter type collar, a regular collar/leash combo, or a leash clipped onto the collar with the other end looped around the dogs neck much like a chain.
Each of these tools can be very affective if used correctly. From my experiences I have found that different tools can work better with different dogs. With Boomer, a dominant boxer mix who tends to hold his head high, I usually use a chain. Because he already holds his head high he makes it easy to keep the chain at the base of his head and right behind his ears. In this position I am able to maintain the most control over his behavior on the walk. I also require him to keep his parallel with me or behind me, never in front of me.
At this point Boomer is far too dominant to be let to roam in front of me. As soon as I allow him to do this his tail goes straight up in the air as he tells me through his body language that he has taken the role of pack leader away from me.
The combination of the chain kept high on Boomer's neck and his body position next to, or behind me gives me the opportunity to give quick, gentle corrections whenever he tries to take over the leader role or when he starts to become aggressive toward other animals, people or cars.
The longer the walk the better the leader follower relationship can develop. This only works when the walk is done with a definite structure and consistent boundaries and corrections.