It was long believed that without the use of some kind of auxiliary power, it's not possible to develop devices that help people walk. However, a small, wearable addition to ordinary shoes has refuted the belief, thanks to US scientists at Carnegie Mellon University and the University of North Carolina. The device has brilliant efficacy to reduce the burden on the calf muscle and enables a person to walk with ease.

Easy walking is believed to help keep people on their feet longer, which offers substantial health benefits. Biomedical engineers Steven Collins and Greg Sawicki analyzed the human walk, which in turn helped them understand that ankles and calves of human beings perform motions similar to a spring coupled with a clutch that intermittently stores and releases energy.

A mechanical device has been developed by Sawicki and his colleagues at Steven Collins at Carnegie Mellon University, capable of performing the same sequence of energy give-and-take outside the body. The device is made up of fiber and metal. The device reduces the amount of energy required for walking by as much as seven percent.

The unpowered ankle exoskeleton is believed by the creators to help people either walk farther with the same amount of energy, or restore the normal movement pattern for people who find walking a bit difficult task.

"We found in basic science experiments that that system, your calf and Achilles tendon, works a lot like a catapult. So, the muscle holds on to the tendon and your body actually stretches your Achilles tendon quite a bit and then stores the energy in the tissue and then it's given back to propel you forward in the world", said Sawicki. According to Sawicki, a wearer needs only a few minutes to get used to the exoskeleton.