Annual Workshop Speaker: Jaroslaw Harezlak

Influence of head impact exposure on sport-related concussions: functional data analytic approach

Jaroslaw Harezlak from the Department of Epidemiology and Biostatistics is Assistant Dean of Research Analytics at the Indiana University School of Public Health in Bloomington, USA.


Sport-related concussion (SRC) is a significant public health problem resulting in over 200,000 annual trips to the Emergency Department in the United States. From a biomechanical standpoint, the concussion mechanism includes head impact resulting in high magnitude head rotational accelerations. Mounting evidence from human studies has demonstrated that repetitive head impact exposure (HIE) contributes to decreased SRC tolerance in contact sport athletes. However, studies focusing on quantifying the relationship between the HIE and incident concussion have suffered from simplistic statistical methods utilized.

In Harezlak’s research, head impact telemetry (HIT) system accelerometry time series data from an NCAA-DoD Concussion Assessment, Research and Education Consortium (CARE) are used to determine the association of HIE to SRC occurrence and post-SRC recovery based on the characteristics of head impacts. Harezlak utilizes a scalar-on-function regression approach to determine the most important head impact features as well as their time-varying influence on the SRC.


Jaroslaw Harezlak is a Professor in the Department of Epidemiology and Biostatistics and an Assistant Dean of Research Analytics at the Indiana University School of Public Health-Bloomington, USA. After graduating from Harvard University and two years of post-doctoral training at the Harvard School of Public Health, he joined Indiana University where he has been since 2007. He has held visiting appointments at Johns Hopkins University and University of Sydney, Australia. Currently, he also serves as an adjunct professor at the University of Wroclaw, Poland. He is a Fellow of the American Statistical Association.

Prof. Harezlak’s interests span a number of medical areas including brain imaging, mild traumatic brain injury, neurodegenerative diseases and physical activity as well as statistical areas including regularization methods, semiparametric regression, and functional data analysis. He has co-authored over 120 journal articles and is an author of the book “Semiparametric Regression with R” with co-authors David Ruppert and Matt Wand. He serves as an associate editor for the journals “Epidemiologic Methods”, “Biostatistics and Epidemiology” and “Sensors”.

Jaroslaw Harezlak at the Indiana University

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