Characterization of inertial measurement unit placement on the human body upon repeated donnings

Accurate estimations of variability in multiple donnings of sensor suites may aid algorithm development for wearable motion capture systems that make use of Inertial Measurement Units (IMUs). The accuracy of any algorithm incorporating these sensors is limited by the accuracy of the sensor to segment calibration. When either sensor placement (use by a non-expert) or limb motion during calibration (natural human variation) vary, the estimations are affected. In this study, 22 participants self-placed IMUs on three locations and performed six prescribed motions during each of these five donnings. For absolute placement of the sensors, the chest location mean was less than the forearm, which was less than the bicep. For sensor orientation, the opposite ordering of location was found. No difference in sensor rotation was found between the bicep and forearm, but both locations differed from the chest location. Results were analyzed at the beginning of prescribed motions.