Evolution of an Adaptable Prosthetic Foot Design for Normalization of Biomechanics During Community Participation

Evolution of an Adaptable Prosthetic Foot Design for Normalization of Biomechanics During Community Participation Summary Abstract The vision of this project is to improve the functional physical mobility of people with lower extremity amputations so that they can more fully and confidently participate in a wider range of activities This will enhance their personal satisfaction thereby improving their quality of life People using prostheses have significant mobility disability compared to their potential partly because commercially available prosthetic feet are unable to meet their day to day needs Also research has shown a high incidence of falls reported by amputees often due to the prosthesis or environment Current prosthetic feet are designed and optimized for level ground forward walking Consequently prosthetists align the prosthetic foot to a single preferred position for this activity During everyday activities including quiet standing feet move about in different positions When the prosthesis user ambulates around their community they are faced with many obstacles that do not conform to the level ground forward walking paradigm Thus there is a need to fundamentally rethink prosthetic foot design to restore adaptability to body ground position The innovative approach pursued in this project is to develop an Adaptable Foot prototype which restores spontaneous adaptability through biomimicry allowing the prosthesis user to ambulate over various terrains The novel spontaneously adaptable foot allows a range of alignments relative to the ground during postures and gait This is achieved by specific linkages that respond to environmental forces with predictable results moving the center of rotation so that it aligns to the resultant forces Rather than incorporating compliant surfaces which can cause postural and gait instability and higher energy cost of gain the Adaptable Foot restores adaptability without sacrificing stability During the Phase I effort the project team will evolve an Adaptable Foot prototype to pass engineering benchmarks that indicate the prototype is ready for extended community use and evaluation Computer simulation will be used to enhance the design of the existing foot and inform engineering aspects of foot prototypes Rapid prototyping and conventional prosthetic manufacturing methods will be integrated to create proof of concept foot designs for standardized performance tests and questionnaire feedback Finally standardized materials testing devices will provide data on energy return and failure modes Project Narrative Currently available prosthetic feet are designed by manufacturers and fit by prosthetist to be optimal for level ground walking and are unable to adapt to various terrains including sloped or uneven ground This lack of adaptability can lead to severe mobility impairment for people using prostheses through a lack of confidence in their prosthetic limb ultimately reducing their community involvement and overall quality of life Here we seek to restore confidence and functionality by creating a prosthetic foot that can spontaneously adapt to the surface geometry and uncertain placement of the foot thereby improving community participation and quality of life