An artificial foot that helps amputees to walk by recycling energy usually wasted between steps has been developed by researchers at the University of Michigan.
Walking naturally wastes energy as each foot collides with the ground between steps but this new device significantly cuts the energy spent per step, compared with conventional prosthetic feet, researchers said.
A typical prosthetic device doesn’t reproduce the force a living ankle exerts to push off the ground, resulting in test subjects spending 23% more energy walking with a conventional prosthetic foot compared to walking naturally.
To test how stepping with their device compared with normal walking, the researchers conducted their experiments with non-amputees wearing a rigid boot and prosthetic simulator.
The test subjects spent 14% more energy walking with an energy-recycling artificial foot, based on metabolic rate measurements, than they did walking naturally, researchers said.
Art Kuo, a professor in the departments of mechanical engineering and biomedical engineering and Steve Collins, who was then a U-M graduate student, developed the foot.