Get the correct size backpack
Heavy backpacks are a strain on many kids' backs. Make sure when picking out a backpack, you buy the appropriate size for your child and that you help your kid understand that packing it too heavy is dangerous.
In regard to backpack safety, pack light. Organize the backpack to use all of its compartments. Pack heavier items closest to the center of the back. The backpack should never weigh more than 10 to 20 percent of your child's body weight.