The design of a compliant composite crutch

Ambulation by crutches takes up to twice the energy of normal gait and can lead to injuries of the hands and arms. The compliant composite forearm crutch described in this article seeks to address these problems. The new crutch is made of a single composite piece and has an S-curve in the main body to provide shock absorption and return of energy with the goal of reducing impact and repetitive injuries. It is lighter and, we expect, more durable than current crutches due to the lack of interfacing parts. The new forearm cuff design provides retention of the crutch on the arm without a pivot. The contoured forearm cuff with wrist supports and padding is intended to provide added comfort and support. These features are integrated into an aesthetic, high-tech-looking design in charcoal/black color. (See Figure 1) Initial testing with seven users yielded favorable response to function and appearance. Quantitative analysis has identified improvements needed for future iteration in design. These include 1) making the wrist supports more narrow and placed down one inch, 2) optimizing the stiffness of the top curve of the S-shape, and 3) testing the crutch for motion and energy requirements in use.