Pretty soon, students will start accumulating school books.
Doctors say don't let that backpack get too heavy as it could cause back problems.
"Hey, I'd like to tell you about books!" said Pre-K student, Maritza Alvarado.
For students like Maritza who love to read, they might pack their backpacks with books.
"Books are so pretty to read. The ones that are mermaids and Little Red Riding Hood," said Alvarado.
"When you look at the weight that you're looking at in these backpacks, it's 20, 30, 40 pounds easy," said Dr. Lawrence Voesack, M.D. of Medical Center Hospital.
Doctors say to prevent muscle pain, students under 13 years old should do their best to avoid carrying a heavy backpack.
"When they carry that backpack just on one side, that's gonna make the muscles on that one side stronger than the opposite side pulling the spine at a curve for the scoliosis to actually make that worse," said Voesack.
An option to relieve or avoid back pain caused by heavy backpacks is to carry it one day on one shoulder, then on the other shoulder the next day. If possible, try and stick with a weight limit too.
"No more than 10% of their body weight. So if you have a child who is 50 pounds, then they should have no more than 5 pounds in that backpack," said Voesack.
Dr. Voesack says he saw fewer children complaining about back pain when backpacks with wheels were allowed in all schools.
As for Maritza, she already prefers a lighter load.