Formerly used only in the aerospace arena, Flexeon is a radical departure from the rigid carbon fiber materials found in most prosthetic feet. It’s a specially- formulated reinforced fiberglass material that is nearly indestructible, extremely flexible, and available exclusively on Ability Dynamic prosthetic devices, such as the RUSH™ foot. Flexeon underwent thorough and extensive testing for flexibility, material strength, and durability in prosthetic labs, as well as on patients aged 21 to 69 in clinical trials. The results of these tests and trials revealed that this high-tech material is three times more flexible than carbon and much more durable than current standard carbon fiber products.

Fig. 1 – The RUSH foot, built of Flexeon, is a flexible, durable, lightweight alternative to traditional carbon fiber feet.
The RUSH foot is designed so that the laminate sequence allows several inches of deflection at the toe during extreme loading, for example, when the user is playing a game of basketball, or sprinting. This allows full energy return to launch the user when dynamic response is preferred. Under less dynamic loading, such as walking, the foot is compliant under any terrain without being too flexible.

Another feature designed into the laminate sequence of this foot is the multiaxial flexibility of the toe without a split toe design. The problem with splitting the toe of a prosthesis is that the toe off of the foot is designed to be more stiff to carry the load on one side of the split.

Two separate design models—the halfrocker and the full-rocker provide an improved gait. The half-rocker is made for the below the knee amputee and the full-rocker for above the knee. These models especially appeal to amputees who have complained that current prosthetic feet have a clear “dead spot” due to the long-standing heel to toe design. The rocker sole eliminates dead spots with a radical geometric shape that runs the length of the foot.

Great engineering is vital to new prosthetic products. The future of prosthetics can be an enjoyable exercise in design that uniquely bridges the gap between the personal and the technological. Future designs, including the RUSH foot and custom rocker, will no doubt inspire the look of the next generation of prosthetics.

This article was written by J. Blount Swain, President of Ability Dynamics. Tempe, AZ. For more information, Click Here .