1. A method for preoperatively characterizing an individual patient's biomechanic function in preparation of implanting a prosthesis, comprising the steps of: a. subjecting a patient to various activities; b. recording relative positions of anatomy during said various activities; c. measuring force environments responsive to said patient's anatomy and affected area during said various activities; d. characterizing the patient's biomechanic function from said relative positions and corresponding force environments; e. inputting the measured force environments, relative positions of knee anatomy, and patient's biomechanic function characterization into one or more computer simulation models; f. inputting a computer model of the prosthesis into said one or more computer simulation models; and g. manipulating the placement of the prosthesis in the computer simulation using said patient's biomechanic function characterization and said computer model of the prosthesis to approximate a preferred biomechanical fit of the prosthesis.