“…The analysis of human motion yields biomechanically related prior information such as joint range of motion (RoM) [18,39,41], segment lengths [18,24,33,34,37,38,40,41,45] and spatiotemporal gait parameters [21,37]. Additionally, the indirect way of measuring kinematics with IMUs placed on the body segments required prior knowledge about the sensor position with respect to the joint center [23,24,29,40,46], sensor to segment alignment [17,29,34,37,40,44,46] and an initial sensor orientation or kinematic estimate [39,44]. Furthermore, three studies described a method to learn a fully subject-specific model [30,31,43].…”