Design and Evaluation of a High-Performance, Low-Cost Prosthetic Foot for Developing Countries

A novel, high-performance, cosmetic, rugged, appropriately costed, and mass-manufacturable prosthetic foot for use in low-income countries was designed and field tested. This ruggedized foot was created to accommodate the unique economic, environmental, and cultural requirements for users in India. A previous prototype that enabled able-bodied like gait was modified to include a durable cosmetic cover without altering the tuned stiffness of the overall foot. After undergoing mechanical benchtop testing, the foot was distributed to prosthesis users in India to for at least 5 months. Afterward, participants underwent clinical tests to evaluate walking performance, and additional benchtop testing was performed on the field-tested feet to identify changes in performance. The ruggedized foot endured 1 x 10(6) fatigue cycles without failure and demonstrated the desired stiffness properties. Subjects walked significantly faster (0.14 m/s) with the ruggedized foot compared to the Jaipur foot, and the feet showed no visible sign of damage after months of use. Additionally, the field-tested feet showed little difference in stiffness from a set of unused controls. Anecdotal feedback from the participants indicated that the foot improved their speed and/or walking effort, but may benefit from more degrees-of-freedom about the ankle. The results suggest that the foot fulfills its design requirements; however, further field testing is required with more participants over a longer period to make sure the foot is suitable for use in developing countries.