Evaluation of Pediatric ATD Biofidelity as Compared to Child Volunteers in Low-Speed Far-Side Oblique and Lateral Impacts

Abstract

In general, the ATDs overestimated lateral excursion in both impact directions, while underestimating forward excursion of the head and neck in oblique impacts compared to the pediatric volunteers. This was primarily due to pendulum-like lateral bending of the entire ATD torso compared to translation of the thorax relative to the abdomen prior to the lateral bending of the upper torso in the volunteers, likely due to the multisegmented spinal column in the volunteers. Additionally, the effect of belt pretightening on occupant kinematics was greater for the ATDs than the volunteers.

Comparison of Q3s ATD Biomechanical Responses to Pediatric Volunteers

“…We acknowledge that though observed differences between the Q3s and PVs may be attributed to nonbiofidelic aspects of the Q3s, these differences could also be due to the difference in seat belt loading. Similar findings as presented here have been found in Q6 and Q10 to PV comparisons, including overestimation of Y and Z head excursion, underestimation of X excursion in oblique impacts, and C4 and T1 downward motion compared to PVs (Seacrist et al 2014). Due to consistency with the older Qseries ATDs, we have reason to believe that the presented data are more likely due to differences in the Q3s design.…”

“…Though the adjusted back rest was successful in providing an appropriate posterior environment for the Q3s, the seat belt angles were not able to prevent seat belt slip up the Q3s rounded thorax. Seat belt slip up the rounded thorax has also been observed in other Q-series ATDs and has been highlighted as a biofidelity issue in itself (Lubbe 2009;Seacrist et al 2012Seacrist et al , 2014. We acknowledge that though observed differences between the Q3s and PVs may be attributed to nonbiofidelic aspects of the Q3s, these differences could also be due to the difference in seat belt loading.…”

“…Force-displacement data were collected in both the muscle tensed and muscle relaxed condition for every volunteer. PV data for the low-speed far-side sled tests were used from 7 subjects ages 6 to 8 years old (6-year-old: n = 2, 7-year-old: n = 3, 8-year-old: n = 2; lateral condition: n = 4; oblique condition: n = 3; Seacrist et al 2014). …”

“…Recently, several studies have taken advantage of pediatric volunteer (PV) data to evaluate the biofidelity of ATDs (Seacrist et al 2010(Seacrist et al , 2013(Seacrist et al , 2014. PV data are more readily attainable compared to pediatric PMHS and are emerging as a valuable tool for evaluation of ATD whole-body kinematic responses.…”

Modeling spatial trajectories in dynamics testing using basis splines: application to tracking human volunteers in low-speed frontal impacts

“…Previously, we have limited comparisons between human volunteer and ATD response to the few children in the data-set who correspond to the ATD size (Seacrist et al 2010(Seacrist et al , 2012 and age (Seacrist et al 2014). The results are consequently more robust to sample size limitations which are common in biomechanical testing.…”