|If it hasn't hit you yet, it probably will. Lower-back blowout will sneak up and humble you, along with some 80 percent of your fellow beings, at least once in your life. The onset will be inglorious: lifting groceries out of the car; roughhousing with a kid; stooping over a derailleur. One day you're active, the next you can scarcely tie your shoes.
Only the common cold prompts more doctor visits than back pain, but given the thinness of some cures, all that experience hasn't netted much. Causal relationships tend to be fuzzy, and the likeliest prescription you'll get is to simply wait. "You have an 85 percent chance of getting better in the first two weeks," says Dr. William Dillin, an orthopedic surgeon at the Kerlan-Jobe Orthopedic Clinic in Los Angeles. "Why try to prove or disprove the exact nature of pain if the progress will be the same?"
But if you really want specifics, acute back pain typically originates in the lumbar region of the spine, where five hardworking vertebrae bear most of the weight of our sitting and standing lives. Because this latticework of bone, cartilage, muscle, nerve roots, and such is responsible for so much, it's particularly susceptible to harm. Unless you have a spinal tumor, infection, or fracture, an out-of-whack lumbar will cause one of two distinct kinds of pain.
Localized pain stems from a mechanical problem, commonly the result of an acute injury to the lower back; you've done something to it. When you strain, tear, or otherwise damage your back muscles, they become inflamed, swell, and push on the surrounding tissue, causing pain. The muscles can even go into spasm, lock up, and restrict mobility of the spine.
The other form of pain — sciatica — is much more insidious. Though it can erupt from injury, the direct cause is the pinching of one or more nerve roots, usually because a disk between two vertebrae gets torn, inflamed, or herniated. Sciatica can also be chronic, perhaps the result of a degenerating disk, a bone chip, or some other recurring pressure on a nerve root. Either way, pain shoots down the back, along the outer side of the thigh, and down to the foot. You may or may not experience localized pain with sciatica.
Happily, whichever type of acute pain you have, treatment is the same. The pain may subside on its own within a couple weeks, but in the meantime we've provided the basics of how to respond if your back flattens you. You can speed recovery. Likewise, you can do a lot by way of prevention within your normal fitness routine. And if you're craving a graphic snapshot of your aching back, consider the upshot of one set of studies in which adults with no back pain were examined using magnetic resonance imaging: Virtually all had bulging disks. So really, the imperfect back is the normal back.