On any given day, 5 percent of Americans — 15 million people — have back pain. Eighteen percent (54 million) have suffered back aches in the past month. And over a lifetime, significant back pain bedevils two-thirds of the population. Not surprisingly, back pain is a leading reason why Americans consult physicians, accounting for 14 percent of primary-care doctor visits.
According to the American Academy of Family Physicians, the most frequent cause of back pain is muscle strain. The injury might result from overuse (a rowing machine) or twisting (a backhand tennis shot), or lifting incorrectly (using the back instead of the legs). But quite often, there is no trauma. You rise from a chair or bend over while dressing, and wham, you feel sharp pain in your back.