This is probably one of the few times I’m not in full agreement with Joe-Joe. Most of my lunge lines do have a chain, but I only run it over the horse’s nose on days the horse chooses to be a blithering idiot and pay no attention to me. When dealing with an animal that outweighs me by a factor of 10, sometimes I need something a little extra to get the horse’s attention back on me, and to make it clear that I am in charge. However, once this is accomplished, I remove the chain from the horse’s nose. For me, the chain is a “discipline” not a “punishment”. I should also add that in spring in fall if the horse starts out with a bit of bucking and kicking, I ignore it, as weather relating “feeling good” issues. Most horses figure out my rules fairly quickly, so if the “feeling good” turns into “let’s be naughty”, instead of “okay, got that out of my system, now I’m ready to work”, having a chain handy & immediately available can be very useful. But once the horse settles down to work, the chain gets removed. Using a chain or not using a chain must also depend on the horse’s reaction to having a chain put over his/her nose. It can backfire and upset the horse more, rather than getting the horse’s attention back on the person at the other end of the lunge line. What works with one horse can be disastrous with another, so one must choose discipline methods based on what works with each individual horse, not based on what worked with one’s previous horse, or one’s trainer’s horse, or best friend’s horse. In short, it can be a useful tool, but is not the only possible tool.
While the English term “lunge” did probably come from French term “longe”, the anglicised spelling is used in most American catalogs, so one checks the index for “lunge lines”, not “longe lines”, and both spellings are usually considered acceptable and correct. Although “longe” might be considered a bit pretentious in some circles, something I know Joe-Joe is not.