Rear Seat Safety for Children in Frontal Impacts PDF Download

Author: Jared Colin Seidel
Publisher:
ISBN:
Category : Biomechanics
Languages : en
Pages : 106

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Book Description
Pediatric fatality rates from motor vehicle crashes (MVCs) have declined over the last 30 years (National Highway Traffic Safety Administration, 2012). This decrease can be a result of updated traffic safety laws and improved car seat design. These advancements present the opportunity to shift focus towards understanding and improving safety for non-fatal injuries. One study found crashes resulting in clinically significant injury (AIS 2+) to children, the lower extremity (LE) was the most frequently injured body region, resulting in 28% of injuries (Arbogast et al., 2002). Jermakian et al. (2007) found in a review of crash data involving a rear-seated child in a front facing child restraint system (FFCRS) whom experienced lower extremity fracture, 76% of injuries occurred below knee (20/26), where 75% (15/20) of the below knees injuries were a consequence of interaction with the front seat back, regardless of the direction of impact. Research completed by the Injury Biomechanics Research Center at The Ohio State University has worked to develop an instrumented LE for the Hybrid III six-year-old anthropomorphic test device (ATD). This modified LE incorporates 6-axis load cells in each tibia and ROM stops to improve ankle biofidelity. This updated LE design was used to investigate the effect of front seat back (FSB) properties, initial leg position, and rear compartment geometries in eight 30 mph frontal impact tests. The FSB properties were designed to mimic the two extreme conditions: impacting a rigid or soft anterior structure. The rear compartment space was adjusted to represent a front seat forward or closer toward the LE of the ATD. Initial positioning of the LE either initially touching the FSB or relaxed was another variable investigated. Tibia force and moment, femur forces, tibia index, excursion distance, and head injury criterion were all parameters examined. Data suggest that when the LE was initially touching a stiff FSB, values were observed that either approached or exceeded injury thresholds. When the LE was initially touching a foam FSB, no injurious values were observed. In all four tests when the LE was initially relaxed, independent of front seat positon, the LE impacted the lower rigid portion of the front seat resulting in values that either approached or exceeded injury thresholds. The ATD-LE was successfully used in frontal impact tests, but improvements can be made to the ankle biofidelity at high speeds in both dorsiflexion and plantarflexion. These data can be used to update front seat properties to improve LE protection and present the value of utilizing an instrumented HII6YO ATD-LE.