Men and women with lower limb amputations struggle with managing the balance between prosthesis alignment and shoe heel rise. A novel prosthetic ankle-feet system is being developed to support a wider range of footwear options for men and women with lower limb amputations. Each rigid foot is customized to fit the footwear of choice and can be rapidly attached to (or released from) an ankle unit which remains attached to the prosthesis.
The ankle unit has a mass of 318g and is small enough to fit in the design volume of a 22cm foot across a range of heel rises. The ankle uses elastomeric bumpers arranged in a wiper design to maximize space efficiency.
Structural testing has shown that the 3D printed custom Nylon 12 feet withstood 4584N of forefoot loading without failure based on the ISO 10328 loading parameters, indicating suitable strength to support safe human use in the laboratory. The feet have a mass of 446g.
Feedback from two women Veterans with lower limb amputations reinforced the importance of improving access to shoes with different heel rises. Future activities will include cyclic fatigue testing, additional weight reduction, and incorporating suggested design refinements.