Book 10, Question 13
Why Do Backpacks Need Two Straps?
Backpacks need two straps so the weight is shared across both sides of your body! That keeps your spine from being pulled sideways. A pack should also be light, so pack only what you need.
More fun facts
- A backpack harness spreads the load between your shoulders and hips.
- Humans have strapped loads to their backs for a very long time, but backpack design took off around the time of the US Civil War.
- The oldest known backpack, found in the Alps on the border of Austria and Italy, used two narrow wooden boards and a hazel rod as a frame.
- On the International Space Station, astronauts wear a backpack style harness with springy straps to stay on the treadmill.
- The straps that connect a load to your body are called the suspension system.
Sources: Smithsonian Magazine, Smithsonian Magazine
Questions kids ask
Why not carry a backpack on one shoulder?
Two straps share the weight evenly, so one side of your body does not do all the work.