E-bikes are everywhere. As people seek more environmentally-friendly methods of transportation, electric bikes, or e-bikes, have gained popularity. The bikes are easy to maneuver on city streets and the electric assist they offer also makes them a good choice for rides in the country.

More than one million e-bikes were imported into the U.S. in 2022, up from 437,000 in 2020. The more than doubling of e-bike use has been accompanied by an increase in injuries, researchers at the University of California at San Francisco (UCSF) recently found, particularly head injuries and hospitalizations.

The numbers are concerning because e-bike use is likely to continue to grow as Congress considers extending the Inflation Reduction Act tax credits given to electric vehicle users to e-bike riders.

The rate of helmet use dropped by more than five-and-a-half percent per year.

Between 2017 and 2022, more than 45,500 e-bicycle injuries occurred in the U.S., according to data from the National Electronic Injury Surveillance System. In almost 5,500 cases, the injuries required hospitalization. E-bike injuries increased 30-fold and hospitalizations rose 43-fold over the five-year period. Injuries to children went from zero to 13 percent of all injuries, while injuries in young adults ages 18 to 34 dropped from 63 percent to 30 percent.

The incidence of head trauma increased at a faster rate than the overall incidence of e-bike injuries. Head trauma from e-bike accidents skyrocketed 49-fold, from about 163 cases in 2017 to about 7,900 in 2022. That may be because the rate of helmet use dropped by more than five-and-a-half percent per year. Only 44 percent of those injured were wearing helmets, and those who did not wear a helmet were almost twice as likely to sustain a head injury. Men and women with e-bike injuries were equally likely to wear a helmet.

It's clear that roads and bike lanes must be made safer for micromobility vehicles such as scooters, the authors point out. In addition, “Studying how infrastructure impacts injury and hospitalization rates would be good to look at,” Adrian Fernandez, a corresponding author on the study, told TheDoctor.

The fact that helmets were not worn was surprising, Fernandez, a urology resident at UCSF, said. He pointed out that though not all the reports used in the study noted helmet use, the fact that only 44 percent of those reports including helmet status said a helmet was worn suggests a need for education. “We can focus some of our educational efforts on encouraging more people to wear helmets for any type of bicycle riding,” he added.

The researchers say further studies are needed to characterize e-bike injuries in relation to those sustained by users of other micromobility vehicles, such as e-scooters, mopeds and conventional bicycles, and to see if riders of conventional bikes sustain different types of injuries than e-bike riders or are more or less likely to wear a helmet.

The study is published in JAMA Surgery.