If you're going to ride an e-scooter, you really ought to wear a helmet. That's the main take-home message from a study conducted by the Austin Public Health Department and the CDC, published this week. The data, gathered this fall in Austin, Texas, found that one in every 5,000 rides ended in injury, and 48 percent of those were head injuries. A total of 190 scooter riders were injured during the duration; just one was wearing a helmet.

Depending where you live, you will either be blissfully unaware of dockless electric scooters or completely sick of them. Like the dockless shared bicycles that often precede their arrival, they represent one of Silicon Valley's bright ideas to solve short urban journeys—so called micromobility— by showing up on city sidewalks overnight, en masse. That has certainly been the case here in Washington, DC, where it can be hard to walk more than a few feet in some areas without tripping over a scooter from Lime, Uber, or the rest. But in common with many of Silicon Valley's recent bright ideas, they aren't without risk.

In January, we reported on a study from Los Angeles that found a high rate of head injuries—and a low rate of helmet use—among injured scooter riders. That research looked at scooter-related injuries seen at a pair of UCLA emergency departments over the course of 12 months. By contrast, this new study examined a much shorter time period in 2018—September 5 to November 30—but cast a wider net, using both county emergency medical service reports and data from nine area hospitals.

Focusing on emergency departments (both studies) and EMS reports (this study) may mean that the more severely injured e-scooter riders are overrepresented in both studies, as minor cuts and scrapes are more likely to be seen by urgent care clinics and the like. Revealing the true extent of e-scooter-related injuries would probably require an ICD code.

160 confirmed and 32 probable e-scooter-related injuries were identified from these records. Of those injured, the overwhelming majority were the scooter rider; only one pedestrian and one cyclist were injured by an e-scooter. The researchers contacted the 190 injured scooter riders and were able to interview 125 of them for the study to gain a better insight into the specifics of their crashes. (The details of the remaining 65 injuries had to rely on medical records.) Just over half the injured riders (55 percent) were male, and just under half (48 percent) were aged 18 to 29.

Experience riding a scooter appears to be a factor; a third were injured on their first scooter ride, and another 30 percent had ridden more than once but fewer than 10 times previously.

This study actually discovered a higher rate of head injuries compared to the LA study—48 percent in total. But multiple injuries were common; 70 percent also suffered injuries to the upper limbs and 55 percent to the lower limbs. More than a third (35 percent) broke a bone, and 19 percent broke more than one, not counting finger and toe fractures.

Injuries resulted from a wide range of scenarios. Fifty-five percent were injured riding in the street, but 33 percent were injured riding on the sidewalk. Sixteen percent of injuries involved another vehicle, but only 10 percent were from actually colliding with another vehicle. An equal proportion of injuries (10 percent) involved a curb, and 7 percent were the result of hitting an inanimate object, like a lamppost. Injuries were more common on the weekend (39 percent) and between the hours of 6pm and 6am (39 percent). But only 29 percent reported consuming alcohol within the 12 hours leading up to their injury. Thirty-seven percent blamed excessive speed, and 19 percent believed that a scooter malfunction was to blame.

Perhaps the most surprising finding of all is that 38 percent reported they would ride an e-scooter again in the future.