The design of a lightweight, low cost robotic knee prosthesis with selectable series elasticity

The loss of a lower extremity severely affects quality of life for hundreds of thousands of leg amputees in the United States, and millions worldwide. The vast majority of these individuals use mechanically passive prostheses that do not provide energy during gait. As a result, leg amputees fatigue quickly, walk more slowly, and have difficulty interacting with their community. To address these deficits, researchers have developed robotic prostheses that use electric motors to provide energy. While these technologies have much promise, their substantial mass, inefficiency and cost are obstacles that remain a challenge to broad clinical applications.