This project embodies the core focus of our research with the objective to predict the optimal behavior of robotic transtibial prostheses to optimize the user’s performance, efficiency, and loading of their limbs based on their individual constraints and needs. We are working in collaboration with Dr. Brian Umberger in the Department of Kinesiology at UMass-Amherst to identify ideal prosthesis behaviors. An innovative simulation-based approach in the OpenSim platform is used to generate system specifications based on the user’s abilities and the constraints posed by their altered anatomy. The central hypothesis is that alternative prosthesis designs can minimize the pressures applied to the residual limb and enhance gait efficiency by optimizing the orientation of the residual limb relative to the ground reaction force vector during gait. In this project we developed the concept of active alignment which realigns the affected residual limb toward the center of pressure during stance. During gait, the prosthesis configuration changes to shorten the moment arm between the ground reaction force and the residual limb. This reduces the peak moment transferred through the socket interface during late stance and increases comfort for the wearer.
The current prosthesis design is the Dynamic Joint Alignment ankle prosthesis. This prosthesis was designed with through an iterative simulation and evaluation process. Dynamic Joint Alignment directs the residual tibia to be more in line with ground reaction forces in order to reduce moment transfer at the socket interface.
supported by the National Science Foundation as part the National Robotics Initiative.