Concerning kids’ backpacks, these are not “backpacks.” These are better called “school” or “convenience” packs. A true backpack carries the load on the hips and waist, with shoulder straps for hold and balance, and does not encourage a stooped posture from carrying the load on the shoulders.

Joseph Kostka
Natrona Heights, Pa.

I am 74 years old, weigh 185 pounds, and frequently carry a backpack weighing 70 to 75 pounds for several hours at a time with no difficulty.