Computational modeling is a vital tool for understanding and evaluating healthy and unhealthy function of the musculoskeletal aspects of the human body. However, the accuracy of the musculoskeletal models depends significantly on the accuracy of the input data used to calibrate various behavioral parameters of the model. To date, most computational models have been built using generic in vitro data, mostly because of a lack of accurate and meaningful datasets from in vivo testing. The next major step in computational modeling is to create subject-specific computational models using calibration data taken from in vivo testing. The overall goal was to develop custom devices that when combined with high-speed stereo radiography (HSSR) techniques allow the measurement of in vivo subject data for use in the calibration of computational models. A leg press, and a knee laxity apparatus, were designed, built, and validated for use with HSSR for in vivo subject-specific data collection.