Predicting Zygoma Fractures from Baseball Impact
Mr. Joseph M. Cormier, Mr. Joel D. Stitzel, Mr. William J. Hurst, Dr. David J. Porta, Dr. Jeryl Jones, Dr. Stefan M. Duma
Biomedical Sciences Instrumentation Symposium. 2006; 42:142-7.
The purpose of this study is to develop injury risk functions that predict zygoma fracture based on baseball type and impact velocity. Zygoma fracture strength data from published experiments were mapped with the force exerted by a baseball on the orbit as a function of ball velocity. Using a normal distribution, zygoma fracture risk functions were developed. Experimental evaluation of these risk functions was performed using six human cadaver tests and two baseballs of different stiffness values. High speed video measured the baseball impact velocity. Post test analysis of the cadaver skulls was performed using CT imaging including three-dimensional reconstruction as well as autopsy. The developed injury risk functions accurately identify the risk of zygoma fracture as a result of baseball impact. The experimental results validated the zygoma risk functions at the lower and upper levels. The injuries observed in the post test analysis included fractures of the zygomatic arch, frontal process and the maxilla, zygoma suture, with combinations of these creating comminuted, tripod fractures of the zygoma. Tests with a softer baseball did result in injury but these had fewer resulting zygoma bone fragments and occurred at velocities 50% higher than the major league ball.
This article is posted on this website with permission from ISA. This article is for viewing only, and may not be reprinted, copied, distributed or forwarded without permission from ISA.