As students head back to school, doctors and teachers are warning parents to take a closer look at what’s inside their children’s backpacks, saying overloaded bags can increase the risk of injury and make the school day harder.

Today’s backpacks often carry far more than textbooks. Many students haul laptops or tablets, chargers, notebooks, water bottles, lunch boxes, sports gear and other personal items, creating loads that experts say can put unnecessary strain on growing bodies.

The American Academy of Pediatrics says parents should watch for signs that a backpack is too heavy, including children leaning forward while walking, struggling to carry the bag or shoulder straps digging into their skin.

Dr. Sadika Kendi, who chairs the academy’s injury prevention efforts, said parents shouldn’t wait until a child complains about pain before lightening the load.

“It’s worse if, for example, they trip and fall and they have a huge, heavy backpack on their back,” Kendi said. “Then that’s just more weight that could increase the severity of an injury.”

Kendi also said there is not enough evidence to support the commonly cited recommendation that backpacks weigh no more than 10% to 15% of a child’s body weight. Instead, she said families should focus on carrying only what is necessary and keeping backpacks as light as possible.

Teachers are also encouraging parents to rethink what students really need each day.

Phoenix history teacher Samantha Ness said many students already have classroom textbooks but are still expected to bring laptops and chargers every day, while some fill their backpacks with non-school items.

“They’re using their backpacks more as purses and like storage than they are actually using them for school,” Ness said, noting older students often carry makeup, nail polish and other personal belongings alongside school supplies.

In Fairfax County, Virginia, some parents are also questioning whether children need to carry both printed textbooks and school-issued laptops, particularly when block scheduling means students may not need every subject every day.

Experts recommend choosing a backpack with two wide, padded shoulder straps, a padded back and multiple compartments to spread the weight evenly. Waist or chest straps can also help reduce strain.

The American Academy of Pediatrics also advises children to lift heavy backpacks by bending at the knees instead of the waist and to clean out their bags regularly to remove unnecessary items.

One safety tip doctors say parents often overlook is taking backpacks off before getting into a car.

“Don’t wear it in a car or any form of transportation while that car is moving,” Kendi said. “It’s just incredibly dangerous.”

She said wearing a backpack while seated can prevent a seat belt from fitting properly, increasing the risk of injury in a crash or sudden stop.