Changes in Brain Physiology Associated With Youth Tackle and Flag Football: A Pilot Study

Principal Investigator: Robert Lynall

Institution: University of Georgia

Title: Changes in Brain Physiology Associated With Youth Tackle and Flag Football: A Pilot Study

Abstract: Nearly 2 million children in the U.S. participate in tackle or flag football. Youth tackle football safety has been called into question, based largely on neuroimaging studies describing negative brain changes (decreased fractional anisotropy, abnormal mean diffusivity) during and after a season in older football players. Several legislators have proposed state laws to eliminate youth tackle football, despite the fact that no one has directly investigated potential brain alterations in youth football. Although considered a limited contact sport that does not lead to head impacts, our preliminary evidence suggests youth flag football players sustain multiple head impacts throughout a season. An emerging technique to measure brain hemodynamic activity is functional near-infrared spectroscopy (fNIRS). This modality has been used to identify reduced connectivity and altered brain activity relative to controls post-concussion, but no one has investigated potential brain alterations across a season of youth tackle and flag football.

Aims: Identify cerebral hemodynamic changes (brain activation, functional connectivity) across a season of youth tackle and flag football relative to healthy non-contact youth athletes.

Study Design: Matched cohort, pre- and post-season observational study.

Materials and Methods: Study participants (9-12 years) will include youth tackle and flag football players (n=15 each group) along with a control group (typically developing children who participate in tennis; n=15). Pre- and post-season fNIRS outcomes will be compared across groups. To account for head impact exposure, on-field head impact biomechanics will be assessed throughout the tackle and flag football season.

Main Outcome Measures: Brain activation (total, deoxygenated, and oxygenated hemoglobin) and functional connectivity (hemispheric coherence) from fNIRS during rest, finger tapping, n-back, Stroop, and balance tasks. Head impact exposure outcomes (impact frequency and magnitude [linear and rotational acceleration]) from all youth tackle and flag football practices and games across a single season.

Significance: Authors have inferred negative late-life outcomes from youth football participation without actually studying brain alterations during youth football. Understanding brain activation and connectivity in youth tackle and flag football players, as opposed to inferring youth football outcomes from retrospective studies, is critical to informing safe-play policies and legislation.

This proposal directly addresses NOCSAE’s core mission to understand the mechanical and biological mechanisms of injury and recovery and represents a critical first step in fully understanding potential risks associated with tackle and flag football in children.