Advancing Commotio cordis Safety Standards Using the Total Human Models for Safety (THUMS)

Area of Science:

• Sports Medicine
• Biomechanical Engineering
• Cardiovascular Research

Background:

• Commotio cordis is a leading cause of sudden cardiac death in youth baseball.
• Current chest protector regulations for Commotio cordis prevention are not fully optimized.
• Optimizing safety requires considering diverse age groups and impact angles.

Purpose of the Study:

• To evaluate Commotio cordis risk response using finite element models.
• To compare deformation-based metrics with force-based metrics for predicting cardiac events.
• To inform revisions of safety standards for youth athletic equipment.

Main Methods:

• Simulated baseball collisions using finite element models for various velocities, impact angles, and age groups.
• Characterized Commotio cordis risk by measuring left ventricular strain and pressure, chest band and rib deformation, and impact force.
• Correlated deformation metrics (rib, chest band) and impact force with left ventricular outcomes.

Main Results:

• Normalized rib and chest band deformation showed strong correlations with left ventricular strain (R²=0.72-0.76) and pressure (R²=0.68-0.77) in child models.
• The NOCSAE force-based metric showed weaker correlation to ventricular strain (R²=0.20) but moderate correlation to pressure (R²=0.74).
• Deformation metrics provided a more consistent and accurate risk assessment compared to force alone.

Conclusions:

• Chest and rib deformation are more reliable indicators of Commotio cordis risk than impact force alone.
• Current safety standards may need revision to incorporate deformation-based risk metrics.
• Future Commotio cordis safety requirements should consider left ventricular deformation for improved protection.