A heavy school backpack can become a real pain in the back - especially for younger students. A North Texas rehabilitation specialist recommends keeping backpacks at about 10% of a child’s body weight and never above 15%, using both shoulder straps and placing heavier items close to the back. Leaning forward, red marks on the shoulders or trouble climbing stairs can all signal that the load is too heavy. As Texas students head back to class, packing lighter may be one of the simplest ways to protect a growing spine.