PROBLEM

We've all heard that kids carry too much in their backpacks. Now a study from the University of California, San Diego has found that how loads are distributed under the straps may also be causing discomfort in the shoulders and back. Thin straps that put excessive pressure on the shoulders may be causing shoulder pain, and an uneven backpack load may contribute to lower back pain. 
SOLUTION

Look for wider straps. They help spread the load so the weight is distributed better on the shoulders. Load both shoulders. Your child may think it's not cool, but putting the straps on both shoulders distributes the weight more evenly and may help prevent back and shoulder problems.

Keep it high. Wearing the backpack too low on the back can concentrate too much pressure in front of the shoulders, so adjust those straps.

Lighten up. The best way to prevent problems is to reduce the load, says Brandon Marcias, the study's lead researcher.