Center for Injury Research and Prevention

Relative Kinematics of the Shoulder Belt and the Torso: Comparison of the Q10 ATD and Pediatric Human Volunteers

TitleRelative Kinematics of the Shoulder Belt and the Torso: Comparison of the Q10 ATD and Pediatric Human Volunteers
Publication TypeConference Paper
Year of Publication2013
AuthorsArbogast KA, Locey CM, Bohman K, Seacrist TS
Conference NameIRCOBI Conference
Date Published09/2013
Conference LocationGothenburg, Sweden
Keywordsanthropomorphic test devices, biofidelity, kinematics, pediatric

Previous studies have raised concerns about the biofidelity of the shoulder belt-torso interaction of the Q10 ATD in frontal impacts in that the belt appears to move close to the neck and offload the chest deflection sensors. This study used the only known pediatric human volunteer sled test data to evaluate this phenomenon. From this previous study, three subjects (n=11 trials) whose anthropometry was within +/-15% of the ATD were compared to the Q10. The ATD and humans were tested according to similar protocols. Restrained subjects were exposed to a non-injurious crash pulse. Photoreflective markers, placed along the belt and on T1 to define the torso, were tracked using a 3D motion analysis system. In both the ATD and the human volunteers, the shoulder belt moved toward the neck during the loading. However in the ATD the magnitude was greater (37 mm versus 24 mm for the volunteers). Similar findings were observed when the lateral belt movement was computed relative to T1 and when normalized by single shoulder width. Although the magnitude of movement was greater for the Q10 compared to the volunteers, two other characteristics were quite similar: first, the rate of lateral shoulder belt movement and second, the tendency for the belt to move lateral and then begin to return toward initial position. Compared to other ATDs that approximate a young adolescent, the lateral movement of the shoulder belt was greatest for the Q10 both when raw values were considered and when presented relative to T1. Overall, these results suggest that the shoulder belt interacts with the torso of the Q10 differently than in humans and may underestimate chest deflection due lateral belt motion towards the neck, ultimately offloading the chest deflection sensor.