Application of Low Cost Inertial Sensors to Human Motion Analysis

In this paper the feasibility of utilizing low cost inertial sensors for human motion analysis is presented. The Xsens MTx sensor is used as the standard for comparison with the Sony Move and the Nintendo Wii (Wii Remote with Wii MotionPlus). Initial tests have been carried out by measuring upper limb range of motion and position tracking. Initial measurements utilizing kinematic modeling indicates that the MTx, whose static angle accuracy is 0.3 degrees, can measure a movement of 10 cm with an error less than 0.05 cm. The low cost inertial sensors are capable of measuring the range of elbow flexion motion whose typical range is 150 degrees with an error no greater than 1 degrees and the Sony Move can track movement of 10 cm with an error less than 0.2 cm. In order to track position the system must include tri-axial accelerometers, rate gyros and magnetometers. This requirement is met by the Sony Move. The outcome is that Wii can be used for measuring upper limb range of motion and the Move for range of motion and position tracking based on the kinematic model.