BOB HIRSHON (host):
Back relief from bungee cords. I’m Bob Hirshon and this is Science Update.
Whether you’re a hiker, a paramedic, or a third grader, a heavy backpack can be a real pain. Now, University of Pennsylvania muscle physiologist Larry Rome has designed an ergonomic pack that can lighten the load and potentially prevent injuries. It’s rigged with a springy, stretchy bungee cord, which allows the load to glide up and down on a frame as you walk. That eliminates the exertion of lifting the pack a few inches every time you take a step.
LARRY ROME (University of Pennsylvania):
If the load doesn’t move with respect to the ground, then it doesn’t have to be accelerated, and there’s no accelerative force.
That may sound trivial, but Rome says these peak forces can double or even triple a pack’s load while you’re walking or running. In contrast, the bungee pack’s effective load stays very close to its actual weight.
I’m Bob Hirshon, for AAAS, the science society.