Electric bikes and scooters are causing a significant rise in brain and spinal injuries among riders and pedestrians in cities, according to new research that experts say demands urgent action on road safety and urban infrastructure.
The study, led by researchers at NYU Langone Health in New York, examined 914 patients treated at a major city hospital over five years for injuries involving bikes and scooters, both electric and pedal-powered. It found that one in three patients sustained a traumatic brain injury, more than two-thirds required hospital admission and roughly 30 per cent needed intensive care.
The scale of the problem has grown sharply. Injuries involving these devices accounted for fewer than 10 per cent of emergency trauma cases in 2018 but had risen to more than 50 per cent by 2023, representing nearly seven per cent of all trauma admissions.
The most common cause of injury was a collision with a car or lorry, making up around half of all cases. Fewer than one in three riders was wearing a helmet at the time of their injury, and those without helmets suffered significantly higher rates of brain and facial injuries. Around one in five patients had alcohol in their system, which was linked to both worse outcomes and lower rates of helmet use.
One of the study's most striking findings concerns pedestrians. Of the 69 pedestrians included in the research, those struck by electric vehicles suffered brain injuries at nearly twice the rate of the riders who hit them.
Injuries were most common between 6pm and 8pm, a pattern researchers suggest may reflect the surge in e-bike delivery traffic during the evening rush.
The findings were published in the journal Neurosurgery on 15 April.
"Our study shows that micromobility injuries are producing serious brain and spinal trauma that demands neurosurgical care at a scale we have not seen before," said Dr Hannah Weiss, a neurosurgery resident at NYU Grossman School of Medicine and the study's lead author. "The data point to actionable solutions, including helmet use, safer bike lane design and enforcement, that could prevent many of these injuries and better protect both riders and pedestrians."
Dr Paul Huang, chief of neurosurgery at NYC Health and Hospitals/Bellevue and associate professor at NYU Grossman, said urban infrastructure must keep pace with the rapid growth of electric bikes and scooters. He called for future research across multiple cities to assess whether protected bike lanes, helmet schemes and speed enforcement reduce the number of brain and spine surgeries being carried out.
The researchers reviewed patient records from January 2018 to August 2023, collecting data on helmet use, alcohol levels, injury type, brain scans, surgical procedures and length of hospital stay.
