PHOENIX -- From Chandler to Avondale, kids are returning to school this week.
But before you send them out the door with a stuffed backpack, Dr. Michael Chang said pay attention to the weight.
"Ideally, a backpack should weigh 10 to 15 percent of your child's body weight," said the surgeon at Sonoran Spine Center.
While studies have shown no permanent damage caused by heavy packs, Chang said about one in three kids will complain of pain after packs hit about 20 percent of their body weight.
"You don't want to wear the backpack with the straps so loose that the backpack weight is below the hips because that swaying back and forth can also irritate the muscles."
Using both straps and keeping the weight evenly distributed is best, Chang said.