@article{ref1,
title="Drill intensity and head impact exposure in adolescent football",
journal="Pediatrics",
year="2022",
author="Kercher, Kyle A. and Steinfeldt, Jesse A. and Macy, Jonathan T. and Seo, Dong-Chul and Kawata, Keisuke",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="BACKGROUND AND OBJECTIVES: The objective of this study was to examine head-impact exposure by intensity level and position group, and to test the hypothesis that there would be an increase in cumulative head-impact exposure between drill intensities after controlling for duration in each level with air recording the lowest frequency and magnitude and live recording the highest: air < bags < control < thud < live. <br><br>METHODS: We conducted a prospective, multisite study in 1 season with players from 3 high school football teams (n = 74). Each player wore a sensor-installed mouthguard, which monitored head-impact frequency, peak linear acceleration (PLA), and peak rotational acceleration (PRA). Practice drills and games were categorized by level of contact. <br><br>RESULTS: A total of 7312 impacts were recorded with a median of 67 (interquartile range:128) impacts per player. After controlling for duration, increases in head-impact outcomes by level of contact were observed (air < bags = control < thud = live). Live drills had higher cumulative head-impact frequency (45.4 ± 53.0 hits) and magnitude (PLA: 766.3 ± 932.9 g; PRA: 48.9 ± 61.3 kilorad/s2) per player than other levels (P <.0001). In comparison, air drills had the lowest cumulative frequency (4.2 ± 6.9 hits) and magnitude (PLA: 68.0 ± 121.6 g; PRA: 6.4 ± 13.2 kilorad/s2). <br><br>CONCLUSIONS: These data support the levels-of-contact system as a practical approach to limiting head-impact exposure in tackle football. Our findings are clinically important, because data have begun to suggest the relationship between chronic head-impact exposure and decline in brain health. Since head-impact exposure was influenced by levels of contact, regulation of the duration of certain drill intensities (eg, thud, live) may associate with reduced head-impact exposure in high school American football.<p /> <p>Language: en</p>",
language="en",
issn="0031-4005",
doi="10.1542/peds.2022-057725",
url="http://dx.doi.org/10.1542/peds.2022-057725"
}