Is a Heavy School Backpack Really Bad for Your Back?

At the start of every school year, the weight of school backpacks becomes a concern for many parents. Can a heavy backpack damage the back, alter posture or contribute to spinal problems?

A recent study published in the European Spine Journal examined 65 healthy schoolchildren under different loading conditions: without a backpack, with a load of 10–15% of body weight, and with a heavier load averaging about 19%. Researchers assessed changes in spinal and pelvic alignment while the children were standing. 

The body adapts to the load

As backpack weight increased, children tended to lean further forward and showed a small increase in thoracic kyphosis. However, these changes were temporary responses to carrying the load rather than evidence of permanent postural alterations. 

The study identified around 16% of body weight as the value that best distinguished children who developed a significant forward trunk imbalance while carrying the backpack. This should not be considered a strict universal threshold, but rather a practical reference. 

Physical fitness also matters

An interesting finding was that children with greater grip strength showed less forward imbalance under load, suggesting that the ability to manage a backpack depends not only on how much it weighs, but also on the child’s physical capacity. 

The practical message is therefore twofold: avoid unnecessarily heavy backpacks, using 15–16% of body weight as a reasonable reference, but also encourage children to stay active and physically fit. And importantly, school backpacks do not cause scoliosis.