Blunt chest impacts: Assessing the relative risk of fatal cardiac injury from various baseballs

Objective: To compare various soft-core baseballs for their ability to reduce the risk of fatal chest-impact injury. Design: This study used a three-rib biomechanical surrogate to quantitatively analyze chest impacts from nine soft-core baseballs and one standard baseball, which served as the control. Impacts were achieved with an air cannon system, with the velocity of impact being 40, 50, and 60 mph. Materials and Methods: The deflection of the three-rib structure at the sternum was measured and used to calculate the viscous criterion, which correlates with risk of chest-impact injury. Measurements and Main Results: Analysis showed that baseballs with lighter mass had a significantly lower viscous criterion ( p < 0.05). Those with a similar mass had no change in the viscous criterion, and the heaviest soft-core baseball had a significantly higher viscous criterion at an impact velocity of 60 mph. Conclusion: The results of this study indicate that soft-core baseballs may not differ from a standard baseball with regard to the risk of fatal chest-impact injury while playing baseball. Other techniques, such as preventive coaching, need to be implemented when trying to improve baseball safety.