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A Test Bed to Examine Helmet Fit and Retention and Biomechanical Measures of Head and Neck Injury in Simulated Impact
Published on: September 21, 2017
Neck injury response to direct head impact
1Biomechanics Research Laboratory, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA. paul.ivancic@yale.edu
Accident; Analysis and Prevention
|May 23, 2012
Summary
Direct head impacts can cause lower cervical spine injuries. Rearward forces create complex neck loads, leading to ligamentous and bone damage, particularly in motor vehicle crashes and sports.
Area of Science:
- Biomechanics
- Orthopedics
- Trauma research
Background:
- Previous studies suggest upper cervical spine hyperflexion from head impacts.
- The exact injury mechanisms and spinal response to direct head impacts require further investigation.
Purpose of the Study:
- To investigate the cervical spine's injury response to direct head impact.
- To document specific injuries sustained by the cervical spine.
- To compare findings with existing in vivo data.
Main Methods:
- Utilized a human cadaver neck model (n=6) attached to a rear impact dummy torso with a surrogate head.
- Applied rearward forehead force using a cable-pulley system with 3.6kg and 16.7kg free-falling masses.
- Recorded head, vertebral, and pelvic motion using high-speed digital cameras and compared spinal rotations to physiological ranges.
Main Results:
- Peak head impact forces were 249N (3.6kg) and 504N (16.7kg).
- Occipital condyle experienced significant posterior shear (205.3N), compression (331.4N), and extension moment (7.4Nm).
- Significant intervertebral extension above physiologic levels occurred at C6/7 and C7/T1, with observed ligamentous and osseous injuries at C6-T1 from 504N impacts.
Conclusions:
- Rearward head shear force generates complex neck loads (posterior shear, compression, extension moment) capable of injuring the lower cervical spine.
- Lower cervical spine injuries in real-world scenarios (crashes, sports) likely result from combined direct head impact forces and torso inertial loads.
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