Scooter riders are getting into serious accidents that result in broken bones and head injuries, according to the first official medical study on the new form of transportation.

Researchers at the University of California Los Angeles examined data from three emergency departments from Sept. 1, 2017, to Aug. 31, 2018, and found that 249 people required medical care from scooter accidents. One-third of those patients arrived at the hospital in an ambulance and needed treatment in the emergency room.

"These injuries can be severe," Dr. Tarak Trivedi, emergency physician at UCLA and the study's lead author, said in a phone interview. "These aren't just minor cuts and scrapes. These are legit fractures."

Electric scooter company Bird first rolled out these vehicles in September 2017 in Santa Monica, California. Now there are nearly a dozen companies that have scooters for rent in roughly 100 cities across the US.

Because the rentable vehicles are so new, federal and local officials haven't started tracking accidents, and the companies have declined to release any statistics. But emergency rooms in various cities, such as Austin, San Diego and San Francisco, have begun to tally injuries. The US Centers for Disease Control and Prevention are also conducting a nationwide study on scooter accident rates.

UCLA's researchers found that the most common injuries were from falls (74 percent), while 10 percent of accidents happened because of collisions with objects. The vast majority of people injured were scooter riders, but about 8 percent of those injured were pedestrians who either were hit by a scooter or tripped over one.

Of the total injuries, 40 percent were head traumas, 32 percent were bone fractures and the remaining 28 percent were cuts, sprains and bruises. The doctors said only 4 percent of injured people were documented to be wearing a helmet.

"There was abysmally low rates of helmet use," Trivedi said. "Going 15 mph without a helmet on is concerning."

The top two scooter companies, Bird and Lime, give riders tips on how to be safe and recommend wearing helmets. But they don't require helmet use. Both companies have said they're committed to safety and public education.

"At Lime, the safety of our riders and the community is our number one priority," Lime spokeswoman Mary Caroline Pruitt said in an email. "That's why every day we're innovating on technology, infrastructure and education to set the standard."

Bird criticized the UCLA researchers for not involving them in the study.

"Bird did not have the opportunity to work with the study's authors or to collaborate with them, and we find the report to be very limited," Paul Steely White, Bird's director of safety policy and advocacy, said in an email. The report "fails to take into account the sheer number of e-scooter trips taken -- the number of injuries reported would amount to a fraction of one percent of the total number of e-scooter rides."

The researchers said they were interested in completing this first study to better understand the public health implications of riding electric scooters and how to keep people safe.

"We're just trying to bring some light to the issue," Trivedi said.  

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