Accuracy and repeatability of the “neutral-zero position” of the lower extremity

This study examines the discrepancy between an assumed neutral-zero position and the actual posture of the lower extremity of young and elderly subjects during the calibration process of an IMU system. The joint angles were calculated using a marker based optical motion capture system. The results showed a moderate repeatability of the pose and significant differences mainly in the knee and ankle joint angle between young and elderly subjects.