3D joint rotation measurement using MEMs inertial sensors: Application to the knee joint

This study investigated a functional calibration method to define the Cartesian bone-embedded anatomical frame necessary to calculate 3D joint angles. This method was combined with an inertial ambulatory system and applied to the measurement of 3D knee joint angles during gait. This combination was compared to a magnetic tracker system associated with a functional and postural calibration method. The measurement errors due to the shank’s soft tissues were also evaluated by the use of a harness. The combinations of the inertial acquisition system with the functional calibration method show good results. The errors obtained with different attachment methods did not show significant differences. The proposed combination constitutes a very promising tool for clinical evaluations. Keywords-component; 3D angle; MEMS based system; calibration method; skin movement.