I don’t normally use a backpack (although I fear my heavy shoulder bag will have me wake up one day with a hunch), but if I did, I would choose the Smart Bag.
The Smart Bag is an ergonomic backpack that makes it easier to carry around heavy textbooks. The inspiration behind the Smart Bag was Malaysian primary students who are typically given more than 4kg of weight to carry to and from school. To ease this daily discomfort, the Smart Bag—which is created out of eco-friendly material—features ergonomic shoulder straps and offers multi-use functions: carry, pull, and ride-on. Thus, the Smart Bag can convert from a backpack to a storage trolley to a mini scooter.