A powered prosthetic ankle joint for walking and running.

Area of Science:

• Biomedical Engineering
• Prosthetics and Orthotics
• Robotics

Background:

• Current prosthetic ankle joints are specialized for either walking or running.
• Passive prostheses have limitations in range of motion and power output.
• A powered prosthetic ankle offers potential to overcome these limitations.

Purpose of the Study:

• To design and evaluate a powered prosthetic ankle capable of both walking and running.
• To assess the system's ability to mimic able-bodied ankle kinematics and kinetics.

Main Methods:

• Developed a controller for seamless transitions between standing, walking, and running with speed adjustments.
• Validated the hardware and controller functionality in a case study using an ankle bypass on a non-amputee subject.

Main Results:

• The Walk-Run ankle successfully mimicked desired torque and angle trajectories during walking and running up to 2.6 m/s.
• At 4 m/s running, ankle angle was matched, but ankle torque could not be replicated.
• Suboptimal spring stiffness was identified as a limiting factor for ankle output power.

Conclusions:

• The powered prosthetic ankle demonstrates promise for versatile locomotion.
• Further investigation is required to determine the transferability of these findings to amputee users.