Cervical Range of Motion of Children and Adult Volunteers

Co-Principal Investigator: Matthew R. Maltese, MS, Children's Hospital of Philadelphia

Below is an executive summary of this project. Please note that this summary describes results and interpretation that may not be final. Final interpretation of results will be in the peer-reviewed literature.


Although pediatric anthropomorphic test devices (ATDs), also known as child crash test dummies, have provided invaluable data to guide the design of automotive safety systems, they are basically smaller versions of adult- sized dummies because child-specific data are not available. Since children are not small adults, the accuracy of child ATD data is limited. Therefore, there is an urgent need to collect child-specific biomechanical data and to improve pediatric ATDs, taking into consideration the profound soft tissue and bone structure changes that occur from birth through young adulthood.

As children grow, the spine undergoes changes to its structure that likely lead to differences in flexibility and overall head movement compared to adults. The “biofidelity” of the neck, in particular, is important because it governs the response of the head, the most frequently injured body region for children in motor vehicle crashes. This study is part of a focus of research at CChIPS that seeks to quantify how the spine bends in response to passive muscle forces using both pediatric and adult volunteers. These findings are being used by CChIPS researchers and others to develop the next generation of pediatric ATDs and computer models to reduce child injury and death from motor vehicle crashes.

During the study, volunteers were placed in passenger restraints and asked to flex their neck while relaxing the muscles surrounding it. Using surface electromyography (EMG) with audio feedback to ensure the neck muscles were relaxed, the researchers tracked the motion of the head and neck using a multi-camera 3-D target tracking system and calculated the neck flexion angle. Findings showed that the neck flexion angle significantly decreased with age and that females tend to have more spinal flexion than males. These results highlight the importance of age and gender in the development of population-specific crash test dummies and point to needed child ATD design changes.

IAB Mentors

Steve Ridella, National Highway Traffic Safety Administration; Rodney Rudd, National Highway Traffic Safety Administration; Steve Rouhanna, Ford Motor Co.; Uwe Meissner, Volkswagen Group of America Inc.