An important element in the treatment of patients with a transtibial amputation is the making of an adequate prosthesis. The fit of the prosthesis to the stump is an important prerequisite for an optimal function. This is an area where, despite innovation, the stump is often subject to pain or wounds. The prosthetic fit is judged in practice by the physiatrist and CPO but there is no standard by which this is done or criteria to validate a good fit. This has to date not been a subject of scientific research. The subject of this research project wil be to determine the essential factors in the fit of the prosthesis with the aim of defining criteria in judging the adequacy of the prosthetic fit in the patient with a transtibial amputation. This can form the base of deciphering fitting related stump problems in these patients.