Exoskeleton for legs

MIT researchers are demonstrating a new robotic exoskeleton leg system that takes the weight off your back when carrying a heavy pack. In recent experiments, they've demonstrated that the contraption can take 80 percent of the load of an 80 pound backpack. The current prototype apparently screws with your natural walking gait, but they're hoping to tweak the design to enable a normal stride. The research was led by professor Hugh Herr, a double amputee whose pioneering research in the Media Lab's Biomechatronics Group is focused on new prosthetic devices. From the MIT News Office:
 Newsoffice 2007 Exoskeleton-EnlargedExoskeleton devices could boost the weight that a person can carry, lessen the likelihood of leg or back injury and reduce the perceived level of difficulty of carrying a heavy load.

The person wearing the exoskeleton places his or her feet in boots attached to a series of tubes that run up the leg to the backpack, transferring the weight of the backpack to the ground. Springs at the ankle and hip and a damping device at the knee allow the device to approximate the walking motion of a human leg, with a very small external power input (one watt).