This work addresses the field of the artificial devices that replace a missing body limb, particularly the prosthesis used upon a transtibial (TT) amputation, also known as ankle-foot prosthesis. A major challenge in designing an ankle-foot prosthesis lies in synthesizing a mechanism that will functionally mimic the missing part of an anatomical leg and, therefore, restoring the normal gait of the amputee. This way, it will be discussed and presented the requirements for a TT prosthesis, the steps that lead to the primary sketches of the prosthetic model and its main mechanism. This work constitutes a preliminary research in the field of the bionic TT prosthesis.This work is supported by the FCT - Fundação para a Ciência e Tecnologia - with the
scholarship reference SFRH / BD/102659/2014, the reference project UID/EEA/04436/2013,
by FEDER funds through the COMPETE 2020 - Programa Operacional Competitividade e
Internacionalização (POCI) - with the reference project POCI-01-0145-FEDER-006941.
Moreover, it is supported by LIACC - Laboratório de Inteligência Artificial e Ciência de
Computadores, reference project PEst/UID/CEC/00027/2015.info:eu-repo/semantics/publishedVersio