As people flood into stores on Black Friday to do their holiday shopping on the cheap, which toys will they be scouring the aisles for? Smart R2-D2, if they think they can beat the hordes, or maybe a drone? Whatever the must-have toys are this year, they probably won’t cause as many injuries as did 2015’s hot gift: the hoverboard (But who knows? There might be an epidemic of parents taking pratfalls on Hatchimal eggs).

Hoverboards were all over the place last year, as were videos and pictures of people getting injured riding them. Interested in quantifying how viral a phenomenon hoverboard injuries were, I played around with a data set from the U.S. Consumer Product Safety Commission, which collects reports of injuries caused by consumer products from 100 hospital emergency rooms across the country. I found that while hoverboard injuries didn’t have a year-long viral explosion, they did have an enormous spike on one particularly high-profile day.

There’s no specific category for hoverboards in the commission’s data; rather, hoverboard injuries are filed under injuries related to “scooters/skateboards, powered.” Nonetheless, my suspicion was that if hoverboards have been as popular as it seems, an uptick in injuries related to their larger product category — which I’ll call “SSPs” for simplicity’s sake — would be apparent.

I brought my data — records from 1997 through 2015 of injuries from SSPs, as well as those from skateboards and unpowered scooters for comparison — to FiveThirtyEight’s charts crew for some discussion of what I could do with it. We talked over how to visualize the about 85,000 injury reports, which you can check out in this Quickdraw video:





FiveThirtyEight: Quickdraw – Hoverboards vs. Skateboards

My colleague Reuben Fischer-Baum pointed out that it could be interesting to compare the rise in injuries caused by these products after each of them debuted or started to catch on, as well as to look at a breakdown of injuries by body part. And Ella Koeze said it could be revealing to break down the injuries by sex and age.

Back at my desk, I started messing around with the data and looking at time trends for all three product categories. Based on the injury curves, skateboards don’t seem to have had much of a viral moment in the past two decades, but scooters definitely did, starting around 2000, probably because of the Razor scooter’s release that year. As for SSP injuries, they only started to take off in December 2015 — likely the hoverboard effect, since the device started to take over the U.S. with the IO Hawk’s debut at the 2015 Consumer Electronics Show, which took place in January of last year. December 2015 is the last month of data in the data set, though, so I couldn’t quite make the chart that Reuben had suggested (which would show how quickly each product grew after it first started to become popular).

But I wanted to learn more about that huge December 2015 spike. I zoomed in closer to look at injuries by day and found that over a quarter of all SSP injuries that month happened on Christmas Day. That’s a big day of injuries — the biggest in the entire data set by far.

It’s unclear exactly how many of these Christmas Day injuries were caused by hoverboards: 16 out of the 53 SSP injuries are attributed specifically to a hoverboard, two are attributed to a “motorized scooter” and the rest don’t detail the consumer product involved. One of the injuries was very Yuletide-specific: A 9-year-old girl fell off her SSP and into a Christmas tree, hurting her right arm. Many of the other Christmas injuries involved people falling off hoverboards while riding around indoors. None were burns, although this past summer, the Consumer Product Safety Commission recalled half a million hoverboards because their lithium-ion batteries weren’t sufficiently protected from overheating and some were catching on fire.

Different types of people get injured in skateboard and scooter accidents. Skateboard injuries skew heavily male: 86 percent of all the skateboard injuries in the database were sustained by men or boys. Scooter and SSP injuries are also disproportionately male, although the breakdown is closer to 60-40 for each.

SHARE OF INJURIES, 1997-2015 AGE GROUP SKATEBOARDS SCOOTERS SCOOTERS/ SKATEBOARDS, POWERED 0-9 yrs 12.6% – 56.1% – 19.5 – 10-19 68.2 – 35.4 – 34.7 – 20-29 13.6 – 2.4 – 9.4 – 30-39 3.6 – 2.2 – 7.4 – 40-49 1.5 – 1.7 – 8.2 – 50-59 0.4 – 1.0 – 7.7 – 60-69 0.1 – 0.6 – 6.2 – 70-79 0.1 – 0.4 – 4.0 – 80-89 0.0 0.2 – 2.1 – 90-99 0.0 0.1 – 0.7 – Skateboard, scooter and hoverboard injuries by age “Scooters/skateboards, powered” includes hoverboards. Source: U.S. Consumer Product Safety Commission

As you might expect, younger people tend to make up the bulk of injuries in all three product categories, although injuries skew a little older for SSPs (perhaps because of the non-hoverboard products that are in this category).

SHARE OF INJURIES, 1997-2015 BODY PART AFFECTED SKATEBOARDS SCOOTERS SCOOTERS/ SKATEBOARDS, POWERED Ankle 13.7% 5.2% 6.7% Wrist 13.0 9.6 7.3 Head 10.6 12.0 15.2 Arm, lower (not including elbow or wrist) 9.7 11.6 7.3 Face (including eyelid, eye area and nose) 6.9 14.8 9.3 Elbow 6.8 5.3 4.7 Foot 5.2 4.1 4.6 Shoulder (including clavicle, collarbone) 5.1 2.9 5.3 Knee 5.0 5.9 7.1 Leg, lower (not including knee or ankle) 4.4 4.8 7.4 Finger 4.3 5.1 2.6 Hand 3.8 2.8 2.0 Trunk, lower 3.5 2.6 5.5 Mouth (including lips, tongue and teeth) 2.3 5.7 2.2 Trunk, upper (not including shoulders) 1.9 1.6 4.7 Toe 0.9 1.9 1.4 Arm, upper 0.7 0.8 1.3 Leg, upper 0.7 1.1 1.7 Neck 0.6 0.5 1.6 Pubic region 0.3 0.5 0.2 Not recorded 0.2 0.4 0.9 All parts of body (more than 50% of body) 0.1 0.1 0.7 Eyeball 0.1 0.3 0.2 Ear 0.1 0.2 0.1 25-50% of body 0.1 0.1 0.1 Internal (aspiration and ingestion) <0.1 <0.1 0.0 Skateboard, scooter and hoverboard injuries by body part “Scooters/skateboards, powered” includes hoverboards. Source: U.S. Consumer Product Safety Commission

If you look at the injury breakdown by body part, skateboards seem to be tougher on the ankles and wrists, while both scooters and hoverboards involve relatively more head and (yikes) face injuries. I was confused by the “internal” category of injuries. How could somebody ingest or aspirate a skateboard or scooter? A clarifying example: An 8-year-old boy fell off his scooter into the grass where he accidentally inhaled a sandspur. Ouch!