Figure 1

Overview of the experimental setup. Arrangement of the knee simulator, KUKA robot, and ultrasonic motion tracking system (ZEBRIS) during execution of the experiments. The coordinate systems of the femur (x_F, y_F, z_F) and patella (x_P, y_P, z_P) are illustrated. Patellar shift is defined as translation of the patella along the mediolateral axis of the femur (z_F) and patellar tilt is defined as rotation of the patella around its proximodistal axis (x_P).