The foundation to the evolution pathways of the transtibial prosthesis is the passive prosthesis. The origins of the passive prosthesis date on the scale of centuries prior to current. Although a passive prosthesis is not in general capable of providing elastic or mechanized energy to the terminal aspects of stance phase of gait, there are still reasons for why the passive prosthesis is still currently implemented. Passive prostheses serve as robust alternatives in challenging environmental settings, and they constitute a feasible contingency for developing countries. Regardless of the specific class of transtibial prosthesis, there exist associated prosthetic components, such as a socket, liner, and pylon. The socket represents the interface between the prosthesis and the residual limb. Between the socket and residual limb exists a liner that generally consists of an energy absorbing medium. The socket and liner are critical for properly fitting the prosthesis to the unique and specific requirements of a person with an amputation. Between the socket and ankle–foot assembly resides the pylon. The pylon generally enables structural support through conventional metallic materials. Recently, geographically localized materials, such as bamboo, have been incorporated as pylons. The foundations of the passive prosthesis, such as the Solid Ankle Cushioned Heel (SACH), provide a significant perspective for the design evolution of the prosthetic technology. A comprehension of the utility of the socket, liner, and pylon enable a synergistic prosthetic design.