1. A method for preoperatively approximating a preferred biomechanic fit of a prosthesis relative to a patient's articular joint, comprising the steps of: a. receiving information concerning a pre-operative physical articulation of the articular joint during at least one pre-operative physical activity of the patient, such information including: i. a plurality of relative positions of the patient's articular joint during the pre-operative physical articulation; ii. a derived force environment of the patient's articular joint during the pre-operative physical articulation; b. inputting the information concerning the derived force environment and the relative positions of the patient's articular joint into one or more computer simulation models; c. inputting a prosthesis computer model into the one or more computer simulation models; d. using the one or more computer simulation models, inputted prosthesis computer model, and inputted information, approximating a preferred biomechanic fit of the prosthesis relative to the patient's articular joint; and e. outputting information concerning the preferred biomechanic fit of the prosthesis relative to the patient's articular joint.