Reports vary. Researchers in Belgium found that 30 percent of school-aged children report back or neck pain from week to week. Another group found that 23 percent of children ages six to 13 have back pain at least once during these childhood years. Some reports are even higher. It's difficult to compare these numbers because each study is measuring something a little different.

It's clear that back pain among children is a significant problem in the United States and around the world, and the problem seems to be getting worse. Researchers will be looking at this issue more closely in the next few years.