Footwear-Based Assistive Technology for Lower Limb Amputees

Abstract

Men and women with lower limb amputations struggle with managing the balance between prosthesis alignment and shoe heel rise. A novel prosthetic ankle-feet system is being developed to support a wider range of footwear options for men and women with lower limb amputations. Each rigid foot is customized to fit the footwear of choice and can be rapidly attached to (or released from) an ankle unit which remains attached to the prosthesis. The proposed system consists of two key components: a transmitter shoe and a receiver shoe. The transmitter shoe is worn on the intact limb and is equipped with sensors, including accelerometers and gyroscopes to capture the wearer's ankle movements accurately. These sensor data are wirelessly transmitted to the receiver shoe worn on the amputated limb, which houses actuators, such as stepper motors, to replicate the natural ankle movements. The hypothesis was that the orientation of the roll-over shapes of these systems would be altered with even small changes in shoe heel height. Seven prosthetic ankle-foot systems were mechanically loaded to determine their roll-over shapes while using a no-heel shoe and a low-heel shoe. This system was developed specifically to allow users the ability to switch between shoes of different heel heights (i.e., it is a heel-height-adjustable system). Additional loading trials were performed with the heel-height-adjustable system in which the ankle alignment was altered to accommodate the change in heel height between shoes.