A study published online April 16 in Prosthetics and Orthotics International evaluated mechanical properties of the Jaipur Foot components in an effort to guide foot design, manufacturing, and reduce weight. The Jaipur Foot prosthesis is suited for people with amputations in developing countries as it utilizes locally sourced, biodegradable, inexpensive materials as well as being affordable and functional. However, no research had yet been reported on the material properties of the foot components.
Mechanical testing was conducted on two types of woods—ardu and cheed—and microcellular rubber, tire cord, cushion compound, tread compound, and skin-colored rubber. Each material was subjected to testing in either tension or compression based on its location and function in the foot. Samples were tested before and after vulcanization. Two-sample t-tests were used to assess statistical differences.
The results showed that though cheed compressed perpendicular to the grain and had a significantly higher modulus of elasticity than ardu, it had a higher density. Vulcanization significantly increased the modulus of skin-colored rubber, cushion compound, and tread compound and decreased the moduli of both microcellular rubber and tire cord, according to the study.
The material property results from the study provided information for computer modeling to assess material construction on overall foot mechanics for design optimization. Ardu wood was ideal based on the desire to reduce weight, and the tire cord properties serve well to hold the foot together, the researchers found.