And How Heavy Is Your Bag?
O piled the things we routinely carry on a scale (total: 15 pounds). Add substantial extras like a laptop, water bottle, or pair of shoes for evening, then factor in a bag that's heavy from the get-go, and you're in trouble. (Do the math: A 140-pound woman should carry 14 pounds at most, according to Medina's 10 percent formula.) Watch, too, that your whole load isn't on the same side: The doctor recommends carrying a bag on one shoulder and a short-handled tote in the other hand, so you're balanced.