A backpack with a suspension system.A new backpack design that uses elastic cords to minimize the pack's vertical motion could lessen less·en v. less·ened, less·en·ing, less·ens v.tr. 1. To make less; reduce. 2. Archaic To make little of; belittle. v.intr. To become less; decrease. bodily strain on wearers and reduce the effort required to carry a load. It could be useful to schoolchildren schoolchildren school npl → écoliers mpl; (at secondary school) → collégiens mpl; lycéens mpl schoolchildren school encumbered Encumbered A property owned by one party on which a second party reserves the right to make a valid claim, e.g., a bank's holding of a home mortgage encumbers property. with books or to emergency personnel and soldiers who sometimes need to sprint while carrying heavy loads, says the pack's inventor, locomotion locomotion Any of various animal movements that result in progression from one place to another. Locomotion is classified as either appendicular (accomplished by special appendages) or axial (achieved by changing the body shape). researcher Lawrence Rome of the Univerisity of Pennsylvania in Philadelphia. Walking and especially running with a conventional backpack put strain on joints and muscles because, with each footfall, the wearer must reverse the downward momentum of both body and load. "When you run with a normal pack, it bounces up and down," and the wearer repeatedly gets "squeezed in the vise between the load and the ground" Rome says. In the new pack, a bungee cord suspends the load from an external frame. While the frame straps firmly to the wearer's back, the load rises and falls Rise and Fall redirects here. For the Belgian hardcore band, click here. Rises and falls is a category of the ballroom dance technique that refers to rises and falls of the body of a dancer achieved through actions of knees and feet (ankles). little with each step. In walking trials, the peak vertical force exerted by a 27-kilogram, suspended-load backpack was just one-sixth that exerted by a conventional, fixed backpack. The new pack also saves the wearer effort:Carrying a 27-kg suspended load Suspended Load is the term for the fine particles that are light enough to be carried in a stream without touching the stream bed. These particles are generally of the sand, silt and clay size, although they can be larger, es pecially in cases of high discharge, such as during required no more metabolic power than carrying a 21.7-kg conventional load, the experiments showed. Rome and his colleagues describe their contraption in the Dec. 21/28, 2006 Nature. Rome had previously designed a backpack that converts energy from the wearer's steps into electricity (SN: 10/1/05, p. 221), and he has created a company to commercialize both products.--B.H. |
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