I have witnessed my 13-year-old son Gideon wrestle with his unwieldy school backpack often enough to nod knowingly when I encountered the NBC News story “Why Bags Are Wrecking Our Backs.”Although much of the online report does focus on youngsters and their hefty textbooks, adults face life-changing dangers as well. And it’s not just backpacks; poorly designed or overly stuffed purses, briefcases, tote bags and wallets can all contribute to back pain and related ailments.In our hectic world, some materialistic people are convinced that a “Fanny Pack” is designed to carry the equivalent of a woman named Fanny. (“Hi, I’m Fanny. And this is my conjoined twin Nanny.