Looking over their retirement checklist, David and Sharron Knisely had all of their ducks in a row except one: David's left knee. "I'd hurt my knee back in the '70s and had had surgery done on it then," David says. "It had been an issue for a long time."
An issue because, although the surgery had repaired the tear, David's knee was never quite the same. "It had just become more and more of a problem," he tells us. "I could walk fine, but doing stairs or any kind of lateral movement had become increasingly difficult."
This story originally appeared on the In the Loop blog.