Oh gosh, I really hate seeing these "leashes" or whatever you want to call them, but then on the flip side, I think about the mothers of twins or triplets, or those who have several kids of different ages with them at one time, what do you do???? Esp. if they are super active.
You talk to them before leaving the house, explain step by step what is going to happen e.g you are going to hold mummy's hand.
Kids usually respond well when an adult tells them what is going to happen, rather than just taking them out without explaining where, why, how and what.