Groundbreaking exoskeleton device literally puts a spring in your step

Millions of years of evolution have enabled human beings to develop a smooth, energy-efficient way of walking.
But, biomechanical engineers suggested on Wednesday, there’s always room for improvement.
They unveiled an unpowered exoskeleton - a small, light, spring-activated device that fits on the lower leg and reduces the energy cost of walking by around seven percent.
“The difference might seem small, but it makes a significant difference for humans,” said Steve Collins of Carnegie Mellon University in Pittsburgh, Pennsylvania.
It’s the rough equivalent of an infantryman being able to march seven percent more in terms of time and distance for the same energy expenditure, or a trekker freed of the energy cost of toting a 4kg backpack, he said.
Exoskeletons - externally-worn devices intended to augment physical actions or strength - have a long history.