Most kids carry their school books and supplies in a back pack.
Many kids are getting injuries and long term back problems from back packs that are too heavy. Here are some guidelines to prevent back problems. In the elementary school years back pack weight is not usually an issue, except on specific days when they have a lot to carry. But in junior high and high school some packs can weigh as much as 20 or 25 pounds. If a back pack is worn the wrong way damage can be done to the spine.