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Tolerance of the cervical spine to eccentric axial compression
Jarrod W Carter1, Grace S Ku, David J Nuckley
1University of Washington, Applied Biomechanics Laboratory.
Stapp Car Crash Journal
|November 11, 2006
Summary
Cervical spine injury tolerance varies with loading direction. Compression-flexion poses a higher risk than pure compression or compression-extension, informing neck injury prevention strategies.
Area of Science:
- Biomechanics
- Musculoskeletal Injury Research
- Spinal Injury Mechanisms
Background:
- Cervical spine injuries from compressive impact loading are severe, often leading to neurological deficits.
- Understanding the cervical spine's tolerance to various loading conditions is crucial for injury prevention.
Purpose of the Study:
- To investigate the impact of axial eccentricity on cervical spine tolerance.
- To quantify the cervical spine's response to different compressive loading scenarios.
Main Methods:
- Dissected human cadaver cervical spine functional spinal units (FSUs).
- Tested FSUs to failure under compression, compression-flexion, and compression-extension using a high-rate MTS load frame.
- Measured six-axis loads and evaluated injury mechanisms, including axial eccentricity.
Main Results:
- Distinct injury mechanisms (p < 0.01) were observed for each loading group.
- Compression and compression-extension failures showed significantly higher axial force (4x) compared to compression-flexion (p < 0.01).
- Neck Injury Criteria (Nij) values were near 1.0 for compression/extension and significantly lower (approx. 0.3) for compression-flexion (p < 0.01).
Conclusions:
- Cervical spine tolerance differs significantly based on the direction of compressive loading.
- Compression-flexion loading results in lower tolerance and higher injury risk compared to other compressive loads.
- These findings provide critical data for refining neck injury reference values and enhancing injury prevention.
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