Experts have been warning of the health risks to children associated with carrying overly heavy school bags.
Awareness campaigns on the ideal weight of a backpack have been launched to educate both teachers and parents, but the situation has so far failed to improve.
The sight of small children walking uncomfortably, weighed down by a backpack, was still noticeable when school reopened for the 2025 academic year.
To heighten awareness of this weighty problem, Thai PBS World spoke to Assoc. Prof Dr Adisak Plitponkarnpim, director of the National Institute for Child and Family Development of Mahidol University, about the effects of prolonged use of heavy backpacks.
He also suggested ways to keep kids pain-free while parents expressed their concerns about the issue and shared strategies to ensure that they stay on the safe side.
The dangers of heavy school bags
Carrying a bag that is too heavy for a long period of time and improper usage can hurt children’s health and well-being, Dr. Adisak notes. It can cause soreness, pain, discomfort, poor posture and postural distortion.
“The weight of the bag can not only affect the muscles and tendons but also the nerves and joints. It’s also bad for the back, the spine, the neck, the shoulders, the arms and the hands. A heavy bag ruins their posture,” he says.
The use of an excessively heavy bag can have long-term effects on children’s health, the pediatrician says, adding that back pain in children increases the risk of developing chronic back pain in adulthood. It can also lead to musculoskeletal disorders including scoliosis, which can cause permanent damage to the spine.
“What concerns us the most about heavy bags is long-term back problems that can affect their life,” he says.
How heavy is too heavy?
While the general guidelines suggest that child’s backpack should weigh no more than 10% to 20 % of what the child weighs. Dr. Adisak recommends limiting the burden to no more than 10% of a kid’s weight to avoid the adverse effects.
“For example, if your child weighs 20 kgs, his or her backpack should not weigh more than 2 kgs,” he says.
In practice, however, most children carry bags that weigh much more than the recommended limit.
A study revealed that about 30% of Pathom 1 and Pathom 2 students carried a heavy backpack exceeding 15% of their body weight, which could lead to health problems. Pathom 2 and Pathom 3 students were found to be the most affected due to overloaded bags.
The bags are heavier due to homework books, textbooks, notebooks, additional reference books, classroom art materials, lunch boxes, water bottles and other stationary items, the study found.
To prevent back problems, Dr. Adisak suggests considering a bag on wheels. He urged users to exercise caution when using it to avoid an accident.
“Bags on wheels are convenient to pull on smooth surfaces. But they can hurt children when they lug it up the stairs,” he says.
He calls on teachers to give clear instructions about the textbooks that children need to carry, pointing out that unclear directions result in students carrying more than needed.
To ease the problem, Dr. Adisak also urged schools to provide lockers or storage facilities at school where students can keep their belongings safely.
“Some schools have no such policy. That means students have to carry all of their things back and forth to school,” the doctor says.
He urged parents to help their child pack their school bag and try to distribute the weight evenly to avoid postural stress.
A backpack that is not properly used can cause back problems and injuries, Dr. Adisak notes.
He recommends users wear both shoulder straps and consider a backpack with a waist belt to help distribute the load.
“If you are wearing a heavy bag on just one shoulder, your body becomes unbalanced, forcing the muscles on one side to work harder. This can lead to strain and pain in the shoulders and the neck areas. When wearing the bag, make sure it sits snugly and is not hanging loose,” he says.
The doctor also suggests schools to make the heavy school bag issue an agenda item for parent-teachers’ meetings to raise their awareness and educate them about this.
Teachers and parents should do random checks on the weight of children’s bags to ensure that they are not too heavy for them to carry.
“Teach children about the weight limits for school bags. Ask them if they feel fine about the weight they are carrying. Make it a habit like making them brushing their teeth twice a day. Checking the weight of school bags can be a good habit. It’s a key self-care behavior needed for good health,” Dr. Adisak says.
Carrying the load worries parents
Heavy shool bags are a real cause for concern to parents.
Yada’s seven-year-old daughter, a Pathom 2 student, who weighs 19 kgs, carries a big bag to school every day even though she keeps some books and her belongings in her desk drawer.
“The bag is overloaded due to the number of textbooks and notebooks she carries to school. A water bottle and stationary items add further weight. I worry if she could trip on the stairs at school because the bag is too heavy,” the mother laments.
She estimated that her daughter’s bag weighs about 3 kgs, which exceeds the recommended 10% of body weight. On the day before an exam when teachers conduct lesson review sessions, her daughter carried a full backpack to school. The mother says she was surprised by the 7 kg weight of the bag, considerably higher than the limit.
“My daughter often complains about the weight of her school bag. I ensure she packs only the things she needs for school and ask if she’s okay with the load she has to carry,” she says.
Yada admits that she’s concerned that the heavy bag would interfere with her daughter’s posture and the growth.
Another concerned mother Judy, is worried that her nine-year-old daughter would have a postural deformity due to her heavy school bag, which is often filled with homework books, textbooks, reference books, a set of colour pencils for art class and a water bottle.
“I help her pack the bag and let her use different compartments to help distribute the weight evenly and avoid postural stress. If she feels that the bag is too heavy, I let her use an extra tote and carry it by hand,” Judy says, urging schools to encourage students to use the drawers of the desks to reduce the load.
Meanwhile, Paiboon, a father of two, encourages his seven-year-old son to use a trolley bag, saying the bag on wheels supports posture and movement, which could help prevent shoulders and back pain.
“It has wheels and handles, so my son can easily pull them along. That takes the load off the back and shoulders,” he says, adding that school allows students to use this alternative bag.
Paiboon’s son is a Pathom 2 student at a special private school that focuses on extra-curriculum activities. He currently weighs 38 kgs.
The father suggests investing in a high-quality trolley bag, saying the wheels of low-quality ones tend to break easily.
Paiboon notes that teachers always check the weight of students’ bags and allow them to carry only homework books and necessary supplies back home.
“There are only three little books, plus a lunch box and a water bottle in my son’s bag. He keeps most of his things in the school locker,” the father said.
Paiboon says he is more focused on his son’s physical, mental, social and emotional well-being than the academic results. He doesn’t buy additional reference books and other materials which are believed to aid children and help them score better in the exams.
“I don’t want to put a heavy burden on my son. What I want most of all is for him to be happy and healthy,” he says.
