Research by Steven H Collins, Carnegie Mellon University, M Bruce Wiggin, and Gegory S Sawicki, both from the Bio Medical Engineering, North Carolina State University, studied the effects of clutched muscle fasciles and the burst of positive mechanical power during walking to create the 'boots' which look like leg brace callipers for the shin.
The boots provides the same functions as calf muscles and tendons during walking. A spring is positioned parallel to the tendon and connected to the wearer's leg using the lightweight, composite frame with a lever at the ankle joint.
A mechanical clutch is positioned in parallel to the calf muscles which engages the spring when the foot is on the ground and disengages when the foot is in the air, to walk expending around 7% less energy.
"The clutch is essential to engage the spring only while the foot is on the ground, allowing it to store and then release elastic energy," explained Dr Sawicki.
Co-author Dr Steven Collins, from Carnegie Mellon University, said that with some more development, the invention had the potential to help people who have difficulty walking.