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Updated: Mar 23, 2026

Modified Drop Tower Impact Tests for American Football Helmets
Published on: February 19, 2017
Inadequate Helmet Fit Increases Concussion Severity in American High School Football Players
Dustin A Greenhill1, Paul Navo2, Huaqing Zhao2
1Department of Orthopaedic Surgery & Sports Medicine, Temple University Hospital, Philadelphia, Pennsylvania dustin.greenhill2@tuhs.temple.edu.
Background:
There is limited information on the relationship between football helmet fit and concussion severity.
Hypothesis:
Poor helmet fit may predispose football players to a more severe concussion.
Study Design:
Descriptive epidemiology study.
Level Of Evidence:
Level 3.
Methods:
Data from concussion injury reports were obtained from the National High School Sports-Related Injury Surveillance System over a 9-year period. Symptoms, duration, and helmet parameters (fit, interior padding) were analyzed for all first-time concussions.
Results:
Data from 4580 concussions were analyzed. Patients who suffered concussions with a helmet that did not fit properly (3.22%), as determined by an athletic trainer, had higher rates of drowsiness (RR, 1.46; P = 0.005), hyperexcitability (RR, 2.38; P = 0.047), and sensitivity to noise (RR, 1.88; P < 0.001); had more symptoms (5.34 vs 4.54, P = 0.004); and had longer symptom duration (P = 0.04). Athletes with helmets lined with an air bladder had greater rates of sensitivity to light (RR, 1.13; P = 0.02), sensitivity to noise (RR, 1.25; P = 0.009), and longer symptom duration (P = 0.004) compared with foam or gel liners.
Conclusion:
An improperly fitted football helmet is a risk factor for a concussion with more symptoms and of longer duration. Concussions of longer duration are also more common in players with an air bladder-lined helmet. Current high school football rules should mandate supervision and maintenance of helmet fit throughout the season, prior to impact.
Clinical Relevance:
Team physicians, athletic trainers, coaches, and high school officials should ensure proper oversight of helmet fit in high school athletes to decrease concussion severity and duration.
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