This chapter presents a quick and efficient approach to perform patient-specific Finite-Element (FE) predictions of the human calf response under elastic compression. The reconstruction of patient-specific material properties of soft tissues is based on two methodologies described extensively in two previous papers [1, 2]. After a detailed description of the implementation of this model, results obtained on four volunteers are presented. The deformed geometry predicted by the FE model is in very good agreement with the MRI scan of the same leg under elastic compression. Eventually , it is shown that elastic compression always induces a partial vein closure but the magnitude of vein closure depends strongly on the position of the vein, on the shape of the leg and on the material properties of surrounding soft tissues.