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(THE CONVERSATION) “Take the stairs!” we’ve all been implored, to help maintain our health. But what if taking the stairs is painful, difficult or, worse, potentially dangerous?

In most public buildings, we can opt for an elevator or escalator ride. But at home (unless you live solely on the ground floor), taking the stairs is usually a necessity, not a choice. And as people lose mobility with age, injury or disease, it becomes more challenging. Stair negotiation is one of the top...