Design of an Underactuated Powered Ankle and Toe Prosthesis

Powered ankle/foot prostheses aim to replicate the biomechanical function of the missing biological limb. Biomechanical analysis shows that while the ankle injects positive energy into the gait cycle, the toe joint dissipates energy. Yet virtually all powered ankle/foot prostheses use custom ankle actuators in combination with carbon fiber foot springs to imitate the function of the missing ankle/foot complex. Here we introduce a powered ankle and toe prosthesis with an underactuated mechanism. The underactuated mechanism connects the toe and ankle joints, providing biomechanically accurate torque and enabling mechanical energy recovery during gait. The proposed powered ankle/toe prothesis is the first device to match the weight, size, and build height of microprocessor-controlled prostheses. Clinical Relevance-A lightweight, efficient prosthesis with powered ankle and toe joints has the potential to improve ambulation in individuals below-knee amputations.

Automated summary

Powered ankle/foot prostheses aim to replicate the biomechanical function of missing limbs, but traditional designs neglect the role of toe joints. This new prosthetic device with an underactuated mechanism provides biomechanically accurate torque and enables energy recovery during gait.