A Low-Cost Inertial Framework for Dynamic Posturography: From Preliminary Validation to Kinematic Integration

This work presents the development and experimental validation of a low-cost inertial acquisition framework for postural stability analysis. The system consists of three custom inertial measurement units (IMU), positioned on pelvis, right thigh and right shank, and a dedicated processing pipeline that includes sensor fusion, sensor-to-segment calibration, and joint angle computation. The system was validated against stereophotogrammetry and a commercial IMU reference, achieving high accuracy in hip and knee flexion-extension (RMSE% < 4.8, r > 0.98). Integrated into a robotic dynamic posturography platform, the proposed framework demonstrated that IMU-derived parameters complement force-platform data, enhancing the interpretation of postural responses and enabling discrimination of perturbation intensity, application point, and patient visual condition.