Time Window of Head Impact Kinematics Measurement for Calculation of Brain Strain and Strain Rate in American Football

Yuzhe Liu; August G Domel; Nicholas J Cecchi; Eli Rice; Ashlyn A Callan; Samuel J Raymond; Zhou Zhou; Xianghao Zhan; Yiheng Li; Michael M Zeineh; Gerald A Grant; David B Camarillo

doi:10.1007/s10439-021-02821-z

Time Window of Head Impact Kinematics Measurement for Calculation of Brain Strain and Strain Rate in American Football

Ann Biomed Eng. 2021 Oct;49(10):2791-2804. doi: 10.1007/s10439-021-02821-z. Epub 2021 Jul 6.

Authors

Yuzhe Liu^#¹, August G Domel^#², Nicholas J Cecchi², Eli Rice³, Ashlyn A Callan², Samuel J Raymond², Zhou Zhou², Xianghao Zhan², Yiheng Li⁴, Michael M Zeineh⁵, Gerald A Grant^{6

7}, David B Camarillo^{2

6

8}

Affiliations

¹ Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA. yuzheliu@stanford.edu.
² Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.
³ Stanford Center for Clinical Research, Stanford University, Stanford, CA, 94305, USA.
⁴ Department of Biomedical Informatics, Stanford University, Stanford, CA, 94305, USA.
⁵ Department of Radiology, Stanford University, Stanford, CA, 94305, USA.
⁶ Department of Neurosurgery, Stanford University, Stanford, CA, 94305, USA.
⁷ Department of Neurology, Stanford University, Stanford, CA, 94305, USA.
⁸ Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA.

^# Contributed equally.

PMID: 34231091
DOI: 10.1007/s10439-021-02821-z

Abstract

Wearable devices have been shown to effectively measure the head's movement during impacts in sports like American football. When a head impact occurs, the device is triggered to collect and save the kinematic measurements during a predefined time window. Then, based on the collected kinematics, finite element (FE) head models can calculate brain strain and strain rate, which are used to evaluate the risk of mild traumatic brain injury. To find a time window that can provide a sufficient duration of kinematics for FE analysis, we investigated 118 on-field video-confirmed football head impacts collected by the Stanford Instrumented Mouthguard. The simulation results based on the kinematics truncated to a shorter time window were compared with the original to determine the minimum time window needed for football. Because the individual differences in brain geometry influence these calculations, we included six representative brain geometries and found that larger brains need a longer time window of kinematics for accurate calculation. Among the different sizes of brains, a pre-trigger time of 40 ms and a post-trigger time of 70 ms were found to yield calculations of brain strain and strain rate that were not significantly different from calculations using the original 200 ms time window recorded by the mouthguard. Therefore, approximately 110 ms is recommended for complete modeling of impacts for football.

Keywords: American football; Head impact sensor; Instrumented mouthguard; Time window; Traumatic brain injury.

MeSH terms

Acceleration
Athletic Injuries / physiopathology
Biomechanical Phenomena
Brain / physiology*
Brain Injuries / physiopathology
Female
Finite Element Analysis
Football / injuries*
Head
Humans
Male
Models, Biological*
Mouth Protectors
Sports Equipment
Telemetry / instrumentation
Telemetry / methods*
United States
Wearable Electronic Devices

Abstract

MeSH terms

Grants and funding