IMHO there is no reason why a cocker can not work on the leg. Of course they are not as flexible as a collie, and so physically can not achieve the heelwork postition that some collies do, but in my very limited experience they are more that capable of achieving a close and stylish heelwork action. Small dogs also experience more leg movement and are affected more by ankle movements when walking on uneven ground than a bigger dog, which is a major drawback if you wish to compete in obedience.
I think it depends a bit on the dog. I would use the same technique on a cocker as I would a collie
. I would use a treat in my left hand and lure the dog into position. Started with small steps at a slow pace so as not to put the dog off by excessive leg movement. Gradually you will find you are able to stand more upright (teaching a cocker heelwork gives you back ache!), move your hand to where it was more comfortable, take bigger strides, and eventually lose the treat.
If your dog prefers a more hands on approach, you could try the treat in your right hand (but in a similar position to where your left hand would be) and your left hand on the dogs shoulder to keep them in close.
In answer to Max x 2...It took me over a year before Storm would give me the sort of heelwork in the ring (without treats) that she did in training (with treats).
