Human posture measurement in a three-dimensional space based on inertial sensors

Posture measurement systems using infrared or vision cameras require a special setting and thus it is difficult to use in daily lives. In this paper, a mobile three-dimensional posture measurement system is developed based on inertial sensors and smart shoes. Since the signals are measured and processed by a mobile computer, the proposed system enables the analysis and diagnosis of postures during outdoor sports, as well as indoor activities. The measured signals are represented as a quaternion in order to avoid the Gimbal lock effect.