Analysis of structural stiffness versus common geometric design parameters in American football faceguard models

Abstract

American football athletes do not presently have a readily available method for quantitatively comparing faceguards. Athletes need the faceguard to protect the face area. Athletes also expect faceguards to not hinder the execution of skilled activities. Due to the lack of defining, quantifying, or evaluating faceguard design parameters, the public’s agency to select the most appropriate faceguard is limited. Furthermore, the lack of quantitative comparison of football faceguards hampers the development and assessment of future faceguard design changes. In this study, nine faceguard styles from four helmet manufacturers were reverse engineered, parameterized, and computationally analyzed for structural stiffness, weight, and visibility to elucidate: design differences between faceguard styles; and the variables pertinent to the respective design metrics using the Pearson’s correlation coefficient. The results indicated the original manufacturers’ designs varied greatly. The most critical design parameter for each faceguard analyzed in this study was the large diameter parameter. The stiffness and mass were highly correlated for each faceguard. The most critical design parameter for visibility was varied; however, the influence of the helmet-compatible frames was not investigated and is hypothesized to influence visual field obstruction greatly. Due to the importance of the large diameter parameter on stiffness and mass and the independence of the visibility metric, manufacturers can innovate the diameter, or cross-section, of the bars to decrease weight and alter structural stiffness without affecting visibility. Since the visibility metrics were negligibly correlated to structural stiffness and mass, future studies may alter visibility without affecting structural stiffness or mass.