A new biofidelic sagittal plane surrogate neck for head-first impacts.
OBJECTIVE
To evaluate a prototype sagittal plane surrogate neck model designed to provide a biofidelic response to head-first impacts with a straightened cervical posture.


METHODS
Published biomechanical studies were used in the design to define the range of motion (ROM) and stiffness in both flexion-extension rotation and axial compression. The neck was tested in a series of head-first impacts on a drop tower to investigate the temporal aspects of the kinetic axial force response for the head and neck. A separate series of flexion-extension tests was conducted in a spinal motion simulator to assess its ROM and bending stiffness.


RESULTS
In impacts with a 104 N axial preload, the surrogate head and neck displayed a bimodal response to force development in agreement with published studies of cadaveric head-first impacts. In bending without an axial preload, the neck had an ROM and bending stiffness representative of cadaveric human spines and it included a large neutral zone, but with the incremental addition of axial preload these metrics were somewhat reduced.


CONCLUSIONS
The model appears suitable for studying the scenario of sagittal plane, aligned column impacts. Further design refinements are required to provide biofidelity in both sagittal bending and head-first impacts using a single level of axial preload. This would be necessary to study impact scenarios where considerable sagittal plane neck rotation occurs at impact. The model has identified some key concepts that must be considered for continued design and improvement of a dedicated dummy neck for head-first impacts.
Nelson
Tim S
TS
Orthopaedic and Injury Biomechanics Group, Department of Mechanical Engineering and The International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.
Cripton
Peter A
PA
D000063:Accidents, Traffic / Q000145:classification*; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000293:injuries; D003198:Computer Simulation; D006259:Craniocerebral Trauma; D006801:Humans; D008348:Manikins; D008954:Models, Biological; D009333:Neck / Q000502:physiology* / Q000503:physiopathology*; D019838:Neck Injuries; D016059:Range of Motion, Articular; D012399:Rotation