It’s good to be prepared, but kids who walk to school or participate in extracurricular activities may be lugging more than their bodies can handle. Lockers and classroom storage aren’t available everywhere — and a child carrying too much weight might not be ready to learn.

As families begin back-to-school shopping, here’s how to know if your child’s backpack is too heavy, and how to lighten their load.

How heavy is too heavy?

The modern school backpack has evolved, but it hasn’t necessarily gotten lighter. Whether students have textbooks, digital devices or both, they often are accompanied by notebooks, water bottles, lunch containers, workout clothes and more. Individually, those items may not seem heavy, but together they can add unnecessary strain to children’s bodies.

According to the American Academy of Pediatrics, signs a backpack may be too heavy include a child leaning forward to support its weight or having difficulty walking. Straps should not dig into shoulders.

Don’t wait for a child to express discomfort or pain to lighten the load, experts say.

Dr. Sadika Kendi, a physician who chairs the academy’s injury-prevention efforts, says back injuries are uncommon but possible, particularly if a child falls while carrying a heavy backpack.

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

Although 10% to 15% of a child’s body weight is often cited as a backpack guideline, there isn’t enough evidence to establish a one-size-fits-all approach, Kendi said. Because children vary in size, strength, physical development and daily routines, caregivers should consider their child’s individual needs and, in general, keep backpacks as light as possible.

Teachers say leave this stuff at home

After families receive back-to-school checklists for classroom materials, they should take an audit of what a child really must carry every day.

Samantha Ness, a history teacher in Phoenix, said parents should focus on making sure children have basic supplies rather than getting caught up in trendy, decorative or expensive items. Her students have access to classroom textbooks but are still expected to carry a laptop and charger each day. As technology becomes more central to schoolwork, some students have stopped bringing paper, she said. They rely instead on their devices, which can also become distractions.

“When considering the things going into their backpacks, how is it going to help them be successful in the classroom?” said Ness, who has been teaching for about 10 years.

In Fairfax County, Virginia, the school district is bringing back math textbooks after a backlash against technology. That was a win for the group Fairfax County Parents for Intentional Technology, but it also means hard decisions about weight in backpacks.

Parents should think carefully about whether a child really needs to carry both books and a laptop every day, said mom Alix Fetch, a spokesperson for the parents group. Some elementary schools don’t require students to take computers home, while others allow parents to opt out, she said. Block scheduling can also mean older students don’t need every textbook every day.

Fetch said her 7-year-old typically carries lunch, a water bottle and occasionally a folder with homework or notes from the teacher. Even that can feel burdensome, she said, particularly when students move between classrooms for activities such as art or music. And the inside of the bag can still be messy.

“Kids are still kids. There’s food in their backpack and water, and they’re scrunching up papers,” Fetch said.

As students get older, Ness said, backpacks can become more personal storage than school storage, carrying items such as makeup, nail polish and hair dryers.

“They’re using their backpacks more as purses and like storage than they are actually using them for school,” she said.

How to carry the load safely

Experts recommend choosing a backpack that fits the child and has two broad, padded shoulder straps, a padded back, compartments to distribute weight and a waist or chest strap to redistribute the load. The American Academy of Pediatrics also recommends teaching children to pick up and carry backpacks safely, including bending at the knees rather than the waist when lifting heavier bags to avoid strain.

Backpacks with wheels can be helpful, especially for children with injuries, but experts say they may be problematic in schools with stairs or crowded walkways, where they can pose a tripping hazard.

Children should remove their backpacks before riding in a moving vehicle, Kendi said, because wearing one can interfere with how a seat belt works during a crash or sudden stop. Instead, place the backpack beside the child, even if leaving it on seems more convenient during drop-off.

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

Regularly cleaning out backpacks can also help reduce unnecessary weight and keep track of notes, permission slips and assignments. Some teachers recommend doing it weekly to catch missing work, spills from leaky water bottles and accumulating crumbs.

___

The Associated Press’ education coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.