A new bungee-cord backpack promises to lighten the load and ease the strain for travellers, hikers, soldiers and even school children.
An article about the new ergonomically-designed backpack in Canada’s Globe and Mail newspaper noted that conventional backpacks take a toll on the upper back, shoulders and neck. The hip moves up between two and three inches with every step when the wearer is walking. A conventional backpack strapped to the body moves up the same distance. That means a 50-pound load feels more like 100 pounds while walking because of the effort required to lift it. While running, that load rises to 150 pounds, and can result in musculoskeletal disorders and injuries.
With the new design, the load is suspended from the frame by a coupling like a bungee cord. As the hip moves up on every step, the cord stretches by the same amount and the load stays at a nearly constant vertical height.
The new backpack was developed by researchers at the University of Pennsylvania, led by Professor Lawrence Rome, and the findings were published in the journal Nature. In 2005 the professor, an expert in biomechanics and the physics of muscle movement, developed a power-generating backpack for soldiers that converts mechanical energy from walking into sufficient electricity to power several portable electronic devices at once.
Source: Globe and Mail