Though check chains may be seen to be out of date by many animal behaviorists, you may still see them in practice, so it's important to be able to advise clients on how to use them correctly. You feed its long chain. You feed one link through the other, and your aim is to make an upside down p shape like so. The chain should move freely within the links. There should be no resistance. As you can see, if placed on the dog like this, there is no room for movement. The lead must be applied to the dog in this position. As you can see, the chain can move freely. This allows the check chain to be used correctly.