A Multimodal Measurement Approach for Analyzing and Characterizing Shaking Dynamics in Shaken Baby Syndrome Using Optical Motion Tracking, Accelerometers, and Force-Sensing Films with Offender-Profile-Aligned Participant Sampling

Shaken Baby Syndrome is the leading non-natural cause of death in infancy, yet its biomechanical mechanisms remain insufficiently understood. The scarcity of clearly identifiable cases and limited reliable validation data hinder a differentiation between abusive and non-abusive injury patterns. Existing shaking studies have primarily examined the motion response of non-biofidelic infant surrogates, leaving the underlying initial excitation unexplored and failing to reflect offender-related demographic profiles or the applied contact forces that may contribute to associated injuries. This work addresses this gap by experimentally characterizing the initial excitation and realistic load cases of shaking events. This study employed complementary, time-synchronized sensor systems to obtain robust and coherent multimodal measurements. After ethics and data protection approval, fifteen participants (aged 21–35) completed pre-study questionnaires to record anthropometrics and screen for exclusion criteria (e.g. musculoskeletal injuries, psychological disorders). The setup combined two marker-based motion-tracking systems (Aruco/Vicon), an accelerometer, and a force-sensing film placed on the palmar surfaces. Grip selection was left unconstrained to reflect natural handling. Participants were instructed to shake the 7 lb, 21-inch dummy fast forcefully in three trials. Trained observers documented all sessions to clarify potential measurement deviations retrospectively. Sensor data are recorded in CSV format and processed and analyzed using Python scripts.