Body to sensor calibration procedure for lower limb joint angle estimation applied to imu-based gait analysis

Inertial measurement units (IMU) are broadly used in gait analysis and have shown to be suitable to measure joint kinematics. The aim of this study is to investigate a calibration procedure to estimate body-tosensor alignment in order to define anatomical quaternions. The procedure was performed in healthy subjects while remaining in standing position. After calibration, lower limb joint kinematics were assessed during gait trials. The results showed that the joint angles measured with this procedure were within the range of gait data reported in the reference literature, with interesting levels of low variation across trials (Table 2). In conclusion, the calibration procedure described in this work is simple, fast and do not require any additional tools or predefined/complex limb movements, which are desirable characteristics for use in clinical scenarios. Although the results were encouraging, further investigations on the reliability of such procedure will be performed in the near future.This research is supported by CNPq (Process #471804/2012-6 and #308529/2013-8) and CAPES (Project #126/2013).Peer reviewe