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Original Investigation
December 13, 2018

Association Between Conventional Bicycle Helmet Use and Facial Injuries After Bicycle Crashes

Author Affiliations
  • 1School of Medicine, University of California, San Francisco
  • 2Department of Epidemiology and Biostatistics, University of California, San Francisco
  • 3Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco
JAMA Otolaryngol Head Neck Surg. 2019;145(2):140-145. doi:10.1001/jamaoto.2018.3351
Key Points

Question  Do bicycle helmets provide sufficient protection to the face during bicycle crashes, and, if so, how much protection do they offer?

Findings  In this cohort study of 85 187 bicycle crashes from records in the US National Trauma Database, helmets were found to not sufficiently protect the face in bicycle crashes. Helmet protective capacity for the face lessens for the mid face and lower face.

Meaning  Bicyclists are at risk for experiencing facial fractures and soft-tissue injuries during crashes, particularly to the mid and lower face; public education regarding potential facial injury despite helmet use may be warranted.


Importance  Bicycling is an increasingly common activity in the United States that is often associated with fall injuries to the head and face. Although helmets lessen head injury, their role in reducing facial injuries is less clear; therefore, it is important to understand the protective capacity for the face in current helmet design.

Objective  To estimate the conventional bicycle helmet’s association with the rate of facial injury after bicycle crashes.

Design, Setting, and Participants  This retrospective cohort study accessed records from January 1, 2010, to December 31, 2014, from the National Trauma Databank, which collects data from emergency departments in US hospitals. Each record pertained to 1 emergency department admission for a bicycle crash. The National Trauma Databank registry data are collected and recorded by incident, which is equivalent to an injury-related hospital admission. All injuries involving patients aged 18 to 65 years for whom data on helmet use and injury were available were included. Statistical analysis was conducted from July 19 to October 17, 2016.

Exposures  Helmeted and nonhelmeted bicycle crashes.

Main Outcomes and Measures  Head and facial injuries among helmeted and nonhelmeted bicycle crashes.

Results  A total of 85 187 facial injuries met inclusion criteria (patient age 18-65 years, availability of helmet use status, and type of injury). Demographic information on bicycle riders was frequently unavailable. Among all injuries, fractures to the head (11.6% [9854]) and face (11.3% [9589]) occurred at similar rates. Helmets reduced head fractures by 52% (from 14.0% [7623] to 7.3% [2231]) and head soft-tissue injuries by 30% (from 15.0% [8151] to 10.9% [3358]), but had lower rates in protecting against facial injuries. While reducing facial injuries overall, the amount of protection with helmet use varied with facial location of the injury. Reduction in facial fractures was 35% (95% CI, 31%-39%) for upper face, 28% (95% CI, 23%-32%) for mid face, and 21% (95% CI, 15%-26%) for the lower face. Helmets were less protective against facial soft-tissue injuries, with a reduction of 33% (95% CI, 30%-36%) in the upper face, 21% (95% CI, 16%-26%) in the mid face, and 2% (95% CI, 0%-6%) in the lower face.

Conclusions and Relevance  Although bicycle helmets provide some protection against facial injuries after bicycle crashes, the level of protection depends on the proximity of the injury to the helmeted head. The lower face is particularly vulnerable to injury despite helmet use.