Aaron Fitzsimmons is the co-founder of Amputee Blade Runners. He went to grad school in Connecticut to learn about prosthetics. He is an inspirational human being who has dedicated himself and his knowledge to helping amputees live fuller, more meaningful lives. In this video, Aaron explains the different varieties of prosthetic gel liners available on the market. The purpose of prosthetic gel liners is to hold a prosthesis in place.