Choose a backpack that is proportionate to the body size and not larger than what is needed. The shoulder straps should be 2 inches wide, adjustable and padded. The backpacks should never exceed 15% of a secondary school child's weight, or 10% of an elementary school child. Ensure the weight is evenly distributed in the backpack, pack the heaviest items closest to the body as this reduces the strain on the back and don't overload the backpack. Wear both straps and adjust them so the pack fits snugly to the body.