Backpack safety - Choosing the wrong backpack and packing it improperly can put strain on the back muscles and may increase curvature of the spine. So when choosing a backpack, select one with two wide, padded shoulder straps and a padded back. Also, remember to always use both straps and pack as lightly as possible. A rolling backpack is a great alternative for students carrying a heavier load but remember that it must be carried up steps. A backpack should never weigh more than 10 to 20 percent of the student’s body weight.