While adults may blame our back problems on old age, childhood activities can also set the stage for future backaches.

Children can suffer low-back pain, too, says Dr. Orly Avitzur, a board-certified neurologist and medical adviser to Consumers Reports. “A heavy backpack is a strong contributor to low-back pain in children,” Avitzur says, adding that carrying a heavy pack for long periods of time, carrying it on one shoulder instead of two, and climbing stairs while lugging a heavy load can exacerbate the problem. Girls and shorter children are more likely to have back pain from backpacks, due to their smaller stature, so it’s important to find one that fits well. (See our free backpacks fitting guide and backpack Ratings (for ConsumerReports.org subscribers only) to find one that suits your child.)

But there are other factors that can contribute to children’s back problems, such as teen smoking, obesity and/or physical inactivity, intensive sports activity, and accelerated growth rate, as well as a family history of back pain.

According to one European study from 2008, sports most likely to cause back pain in children include jogging and gymnastics. Only one sport led to less-frequent back pain: swimming.

What can parents do? It’s important to take a child’s back pain seriously, says Dr. Avitzur, especially if they are physically active. Things to be aware of:

• Reduce the risks. If your child uses a backpack, lighten the load to about 10 percent of the child’s body weight. While the American Academy of Pediatrics recommends that children carry no more than 10 to 20 percent of their body weight, Consumer Reports’ medical experts think it should be more toward the lighter end.
• Carry with care. Limit backpack use to only when it’s essential, and use both straps of the backpack along with any chest straps, to distribute the weight evenly. (See our free backpacks report for more information.)
• Watch for signs. If your child experiences back pain with a fever, regular back pain at night, or pain that wakes him up, that could be a sign of a serious condition such as a tumor or infection.
• Pay attention to pain. Back pain that shoots down the leg could be due to a herniated disc in the spine. Chronic, unrelenting pain can be due to developmental problems or arthritis. Back pain may also be an indicator of psychological problems stemming from stress, anxiety, or social problems.

In any case, talk to your child and his or her pediatrician about the back pain to get proper care for the problem.