Abstract
The purpose of this research was to develop a preliminary design of a powered pediatric
prosthetic ankle. Previous research identified the health risk of improper gait cycle and the lack
of powered prosthetic ankle options for children. Costs for powered prosthetic ankles are too
high (upwards of $5000 NZD), the sizes are too large and the weight is too significant for a child
to benefit from. Current technologies for ankle joint actuation and materials for the prosthetic
structure were evaluated and a conclusion of utilizing PPAMs was chosen due to their ability to
generate the required 300 N of contraction force. CAD was used to model the structure of a
prosthetic ankle and evaluate the FOS of the different material combinations while under static
loading and fatigue simulations. HDPE and UHMWPE failed to withstand the simulations, while
the aluminum alloy and stainless steel showed minimal faults from the simulations. MatLab was
used to simulate the desired PPAM dimensions of 100 mm to determine the contraction force
and contraction percentage that can be generated by the PPAM. The smallest PPAM found in
research was 110 mm and showed promising results from their mathematical modeling. The
overall height of the prosthetic was no greater than 110 mm and the membrane length of the
PPAM was no greater than 100 mm, while successfully producing more than 300 N during
contraction. The results showed promising data that needs further development to allow the
benefits of this research to positively impact the lives of pediatric amputees.