No Association Between Fencing Response After Concussion and Recovery Time, Concussion Severity, or Clinical Outcomes in Professional American Football Players.

Abstract

The relationship between tonic posturing (also known as the "fencing response") after concussion and clinical outcomes is unclear. The objective of this study was to compare clinical outcomes between professional American football players with a documented fencing response after concussion to players without documented fencing response after concussion. Players with a fencing response after concussion were matched 1:2 to players without documented fencing response after in-game concussion by age, position, and concussion history from the 2018 to 2023 seasons. The primary outcome measure was number of days until return to full participation. Secondary outcome measures included screening of neurocognitive function with the Standardized Assessment of Concussion (SAC) and modified Balance Error Scoring System (mBESS), and subjective symptom reporting with the Sport Concussion Assessment Tool-5. An independent-samples median test compared game-day SAC and mBESS outcomes between groups. A Kaplan-Meier curve evaluated fencing response after concussion on days until return to full participation. A linear mixed-effects model for 11 Sport Concussion Assessment Tool-5 total symptom scores (ie, day of injury up to postinjury day 10) compared symptom recovery over time between fencing groups. Fifty-seven fencing responses were documented over 6 seasons. Nearly 2-in-3 players with a fencing response played defensive back or wide receiver. There was no difference between players with a fencing response (median = 10 days) and those without fencing response (median = 9 days) in days until return to full participation ( P = .16). Fencing response was not associated with a change in hazard for days until return to full participation (χ 2 = 0.91; P = .34). There was no difference between groups in SAC scores ( P = .18-.99) or mBESS score (fencing: 4, nonfencing: 4; P = .87). There was no difference between groups in symptom scores over time (β: -0.02; P = .92). Fencing response after concussion was not associated with symptom recovery, concussion severity, or short-term recovery in professional American football.