Eleven-year-old Aaron Ohebshalom had just finished playing basketball at a friend’s house when he spotted a hoverboard that belonged to the friend’s family. The motorized, self-balancing devices have gone viral over the past year, becoming favorite gifts for tweens and teens. Like many kids his age, Aaron was eager to see what a hoverboard could do. So he stepped aboard.

Ohebshalom has always been a gifted athlete—obsessed with Derek Jeter and LeBron James. He plays point guard on a traveling basketball team. And he didn’t need much time to find his balance and get rolling.

It wasn’t until he tried to turn the device that he lost control. The hoverboard shot out from underneath him and his head slammed into the pavement, leaving a nasty bump. He wasn't wearing a helmet. He never lost consciousness, but he did complain of a headache when his mother arrived to pick him up.

Later that night, Aaron woke up disoriented, according to his mother, Shadi, the cousin of a Consumer Reports employee. “He didn’t even know who I was,” she says. A short while later, Aaron vomited and his parents rushed him to the hospital near their Long Island home. “That’s when they discovered a subdural hematoma—bleeding on the brain above the front left eye,” says Shadi.

Safety Concerns

Hoverboards (which, for the record, don’t actually hover) are two-wheeled, battery-powered machines that resemble skateboards, and can move at speeds greater than 10 miles per hour. There are many brands, but they all work in much the same way. Increasingly, they’ve become controversial.

The devices haven’t been around long enough to collect reliable sales figures, but the Consumer Product Safety Commission (or CPSC) has identified 39 emergency room visits related to hoverboard falls since August. In the last year, they’ve leapt from trade shows to YouTube videos to the Tonight Show (beneath the feet of Jamie Foxx) to playgrounds and city streets all across the country. They’re now featured in the December gift guides of many consumer magazines.

But the backlash against hoverboards has been as swift as their rise. Within the past two months, they’ve been banned from public streets in New York City and throughout the United Kingdom—and many airports, airlines, and shopping malls have restricted them, too. Amazon recently removed most models from its website in the wake of news reports blaming the devices for starting fires. (Consumer Reports reached out to Amazon for comment, but the company did not immediately respond.) The Consumer Product Safety Commission is currently investigating at least 11 such incidents. And Overstock.com has stopped selling the boards altogether, citing safety concerns.

For Aaron Ohebshalom, recovery has a long and painful process. He suffered headaches, dizzy spells, sensitivity to noise and light. He could do very little but sit and wait for his brain to heal. In the end, he missed a full month of school. He’s still not cleared to play sports. In fact, a neurologist has advised him to refrain from even playing his trumpet for the time being. “It’s awful to see him like this,” said his mother a few weeks after the fall. “It was just one second, but it’s left weeks of stress for him.”

“I don’t like this toy,” she added. “I’ve seen what it can do.”

So can these scooters be a worthwhile gateway to high-tech fun, or are they an inevitable accident waiting to happen? Are they easy to ride, or just a frustrating waste of time and money? Given the intense fascination and all the safety questions surrounding them, we decided to purchase a few hoverboards and test them out.

How We Tested Them

We bought three models from Amazon—each at a different price point: a $400 Swagway X1, a $600 MonoRover R2, and an $830 Chic Smart S1. (At the time we published this article, none of these three models was still available on Amazon's site.)

Once the boards arrived at our labs, about 50 people learned to ride them—on carpet, tile, and asphalt. We ran them up and down a ramp in the office and up and down hills on the Consumer Reports campus.

It was not hard to find test subjects. People routinely dropped what they were doing to come see the boards in action. When offered a chance to mount them, most eagerly accepted. The boards are fun to ride—there’s no denying that. They respond in thrilling ways to subtle shifts in balance. They can zip forward, inch backward, swerve from side to side and loop around in a pirouette-like circle. If you haven’t yet seen the hoverboard dance video featuring Justin Bieber's hit song What Do You Mean, check it out. It really captures the magic of gliding on a hoverboard.

How Do They Work?

Hoverboards remain level using advanced motors and controls. The speed and direction of each wheel is controlled individually, based on the pressure applied to the footpads on either side of the board. Press with your toes and the board moves forward. Press with the heels and it moves backward. Press with one toe and the other heel, and the device turns in a very tight circle, like a zero-turn mower.

Hoverboards are relatively fast, too, with claimed speeds between 6 and 12 mph. At higher speeds, riders have to lean forward, ahead of the board, to supply the pressure needed to keep them zipping along. And that can leave readers vulnerable to face-first injuries when things go wrong.

In our tests, we found that an unexpected obstruction—even a small stick, pebble, dip, or bump in the sidewalk—can jolt the rider into shifting his or her weight from one side to the other. That shift can make the wheel on one side speed up or slow down, forcing the hoverboard into an unplanned turn. When that happens, it’s very easy to fall: At any speed, the rider’s feet can  quickly be swept away, with the potential for hitting one's head, much like Aaron Ohebshalom did.

In short, hoverboards are almost too responsive.

What We Recommend

Before you first step onto a hoverboard, find yourself a spotter. Because the board begins to move the moment you apply pressure, it helps to have someone strong at your side, holding your hand, ready to catch you if you lose your balance.

And, always, always, always wear a helmet—a skateboarding or dual-use helmet is preferable to a bicycle helmet. There’s no predicting when or how you’re going to fall and it happens so quickly that you have no time to react. If you’re lucky, you can leap off the board and regain your balance. If not, you can get seriously hurt. One of our engineers experienced two scary spills during testing—despite hours of experience riding the boards—and he was fortunate to escape with only a few bruises because he wore a helmet (and pads, after his first fall).

Stay away from traffic, too. A recent death in England resulted from a fall that might only have been bruising if a bus had not been driving past.

The injuries reported to the CPSC include fractures, sprains, contusions, and lacerations. So, if you’re planning to speed around on the board, you should also consider knee, elbow, and wrist guards.

What to Think About When You're Buying One

These are not brand-name products. They’re generally purchased from Chinese factories by small companies you’ve probably never heard of (we hadn’t). These companies then turn around and sell the products in the U.S.

They’re not as rough-and-tumble as they seem. Some consumers have complained about the boards snapping apart in the center, where the deck narrows. Others have purchased boards that simply stopped working (our Swagway included). Warranties vary from six months to one year and generally cover only defects in material or workmanship. For more details, be sure to check the manufacturer’s website.

Price may not indicate quality. Although brands at the high end of the price spectrum claim to use superior components, we could not easily verify that. We didn’t have time to dismantle the boards and test individual parts, but we did remove the outer shells and take a look inside. The design and construction for all three was strikingly similar.

They’re barely regulated. Aside from New York City and the U.K., the National Conference of State Legislatures is not aware of any other governing bodies planning to take action. The CPSC suggests that you look for a certification label like UL before buying a hoverboard. The models we purchased each had at least one CE label (the European Union equivalent of UL); one had the label only on its charger, one on its box and on its charger, and the third on the charger, the box, and the device itself. The CPSC also advises customers to report any unexpected falls or issues involving the electrical components—shocks, overheating, fires—to saferproducts.gov.

Be very careful when charging them. Due to the threat of fire, the CPSC and Consumer Reports both advise you to monitor boards carefully when recharging the battery. Do not do leave them plugged into an outlet overnight or when you’re away from home. However, not all fires have started while the devices were being charged—in several instances, boards reportedly ignited while they were being ridden.