Toward a more robust lower neck compressive injury tolerance-an approach combining multiple test methodologies.

Area of Science:

• Biomechanics
• Spinal Injury Research
• Forensic Science

Background:

• Cervical spine compressive tolerance is traditionally measured by axial force at failure.
• Axial force tolerance is sensitive to vertebral alignment and test end conditions.
• Current injury criteria may not fully capture complex loading scenarios.

Purpose of the Study:

• Develop a methodology to combine diverse experimental data for evaluating eccentricity-based injury criteria.
• Assess the robustness of current and proposed injury criteria for the cervical spine.
• Improve the definition of compressive cervical fracture tolerance.

Main Methods:

• Combined data from dynamic experiments on whole cervical spine and head kinematics.
• Transformed loads to the C7-T1 intervertebral disc center.
• Calculated resultant force eccentricity and evaluated its correlation with failure loads.

Main Results:

• Accounting for force eccentricity reduced scatter in failure data compared to axial force and moment.
• Resultant force and anterior eccentricity showed improved correlation (R²=0.56) versus axial force alone.
• Sagittal plane extension moment did not correlate with compressive failure load (R²=0.001).

Conclusions:

• Combining resultant force and load eccentricity correlates with cervical damage type.
• This approach shows promise for better defining compressive fracture tolerance in male postmortem human subjects.
• Further data expansion is needed to evaluate robustness across varied loading and postures.