Biofidelity Evaluation of a Prototype Hybrid III 6 Year-Old ATD Lower Extremity

Incomplete instrumentation and a lack of biofidelity in the extremities of the 6 year-old anthropomorphic test device (ATD) pose challenges when studying regions of the body known to interact with the vehicle interior. This study sought to compare a prototype Hybrid III 6 year-old ATD leg (ATD-LE), with a more biofidelic ankle and tibia load cell, to previously collected child volunteer data and to the current Hybrid III 6 year-old ATD (HIII). Anthropometry, range of motion (ROM), and stiffness measurements were taken, along with a dynamic evaluation of the ATD-LE using knee-bolster airbag (KBA) test scenarios. Anthropometry values were similar in eight of twelve measurements. Total ankle ROM was improved in the ATD-LE with no bumper compared to the HIII. The highest tibia moments and tibia index values were recorded in KBA scenarios when the toes were positioned in contact with the dashboard prior to airbag deployment, forcing the ankle into axial loading and dorsiflexion. While improvements in the biofidelity of the ATD-LE are still necessary, the results of this study are encouraging. Continued advancement of the 6 year-old ATD ankle is necessary to provide a tool to directly study the behavior of the leg during a motor vehicle crash.