Teen TV viewing is to blame for boom in back pain.
Those who planted themselves in front of the TV or computer for 15 hours a week or more were three times as likely to have lower-back pain as their more active counterparts (the average American teen watches 3 hours of telly a day). "They sit with their low back flexed--really hunched over--for hours," explains lead researcher Astrid Noreng Sjolie, PhD, a consultant at the University of Bergen.
Kids who walk or ride their bikes at least 1 mile daily can cut their back pain in half; those activities give still-developing spines a chance to stretch out.