The AMP-Foot 2.0 : A Powered Transtibial Prosthesis That Mimics Intact Ankle Behavior

Almost all of the transtibial prostheses that are available on the market are purely passive devices. These prostheses store (potential) energy in an elastic element during the controlled dorsiflexion phase of stance and release it right after in order to move the body forward. As a result of this, only the energy which has been stored can be used for push-off and thus for propulsion. There exists a few prostheses using active components to add extra energy to the system but most of them are still on a research level. In this article, the authors propose a new design of an energy efficient, powered transtibial prosthesis to mimic intact ankle behavior. The main idea behind the AMP-Foot 2.0 is to have the actuator work longer with a lower power rating while the produced energy is stored in elastic elements and released when needed for propulsion. The device is designed to provide 100% of push-off for a 75 kg subject walking at normal cadence on ground level. Keywords— Trans-tibial, Prosthesis, Amputation, Rehabilitation, Robotics