WINSTON-SALEM, N.C. –
June 21, 2017 – Youth football teams
are more frequently exposed to more forceful head impacts as they move up in
age- and weight-based levels of play, according to researchers at Wake Forest
Baptist Medical Center.
Their study, published in the June issue of the Journal
of Neurotrauma, employed in-helmet sensors to record head impacts in youth
football players. They collected the number and location of impacts and the
linear and rotational acceleration they caused to the heads of 97 players ages
9 to 13 in one youth football organization. Data was collected during practices
and games at three different age- and weight-based participation levels during
at least one of four seasons
“By recording more than 40,000 head impacts, this study
represents the largest collection of biomechanical head impact data for youth football
to date,” said study author Jillian Urban, Ph.D., assistant professor of
biomedical engineering at Wake Forest School of Medicine, a part of Wake Forest
Baptist. “Our findings show a trend of head impact exposure increasing with
increasing level of play, but with variability within levels of play.”
The three levels studied were Level A (players 11 and
under weighing up to 124 pounds), Level B (players 12 and under weighing up to
139 pounds) and Level C (players 13 and under weighing up to 159 pounds).
In their analysis of the data the investigators found
that Level C had significantly greater linear head accelerations than Levels A
and B and that both linear and rotational accelerations were significantly
greater in competition as opposed to practice in Levels B and C.
The researchers also found that while approximately
two-thirds of all head impacts in the three levels occurred during practice, the
percentage of high-magnitude impacts was higher in games and the number of such
impacts in games increased with the level of play.
“Our results are consistent with prior
studies of high school and college athletes showing that head impact exposure
increases with increasing age and level of play,” Urban said. “But they also
show differences from one level to the next in a single youth organization.
“Further studies that take into consideration
the various levels of youth football could guide evidence-based intervention
efforts, such as changes in practice structure and game rules, to reduce the
number of high-magnitude impacts, impact frequency and the total number of
impacts with the ultimate goal of improving safety in youth football.”
The research was supported by National
Institute of Neurological Disorders and Stroke awards R01NS094410 and
R01NS082453. Additional support was provided for Urban by National Center for
Advancing Transitional Sciences grant KL2TR001421 and the Childress Institute
for Pediatric Trauma at Wake Forest Baptist Medical Center.
Co-authors are Christopher T. Whitlow, M.D., Ph.D., Joel
D. Stitzel, Ph.D., Mark A. Espeland, Ph.D., Mireille E. Kelley, M.S., Logan E.
Miller, M.S., and Derek A. Jones, M.S., of Wake Forest Baptist and Joseph A.
Maldjian, M.D., and Elizabeth M. Davenport, Ph.D., of University of Texas
Southwestern Medical Center, Dallas.