Years ago, a dog trainer we worked with advised us against extendable leashes. "Your dog should never be in front of you," he told us, "much less more than a few feet away." I sheepishly reeled my dog in from the tree she was sniffing and pressed the lock on the handle.
We immediately purchased a six-foot cloth leash and donated the others to the animal shelter. After that we side-eyed all the dogs criss-crossing 12 feet ahead of their walkers, while virtuously keeping our dog a foot or two to the left. Well, that was the ideal, more often than not there was some tugging. Our wrists grew mighty strong, though, and so did our dog's neck. Eventually, we found a balance, and our dogs have been very nice walkers, both.
This evening I looked out the window and saw our neighbor walking her 15-year-old dog. She uses an extendable leash, but rather than run ahead of her, her dog stopped and she was the one who continued walking until she got to the end of the leash. Only then did she turn around and see her recalcitrant pup. "C'mon," she encouraged him, and he lumbered forward. Then she turned and kept going, unaware that he had stopped again. They made their way all the way home just like that, 12 feet at a time.