Imagine gliding through leafy treetops with a bird’s-eye view of the earth below. Now imagine falling from that great height and winding up with serious bruises, broken bones or worse.

According to a new study looking at the number of non-fatal injuries caused by zip line accidents, such scenarios are increasingly common. By analyzing statistics from a national database of emergency room visits, experts at the Center for Injury Research and Policy of the Research Institute at Nationwide Children's Hospital in Columbus, Ohio, found that since 1997, more than 16,000 people were injured badly enough while zip lining to go to an ER.

What’s more, the injury rate from zip lining increased by more than 50 percent between 2009 and 2012. The researchers chalk this up to the growing popularity of the sport, which really took off in 2009.

Related: Staying Safe at an Amusement Park

Thrills — and spills

Zip lining often is a feature of adventure travel tours as well as summer camps and outdoor adventure programs. It involves buckling into a harness attached to an overhead cable that slopes downward, allowing gravity to pull you from the top of the cable to the bottom, often at fast speeds. In the United States, the number of commercial zip lines grew dramatically during the last four years of the study, from just 10 in 2009 to 200 in 2012.

The study found that most zip line accidents involve either falling (77 percent) or slamming into trees or other structures (13 percent). The most common injuries caused by these incidents were:

  • broken bones (46 percent)
  • bruises (15 percent)
  • strains or sprains (15 percent)
  • concussions or other closed-head injuries (7 percent)

Most people who get hurt while zip lining are kids. In the study, children younger than 10 accounted for 45 percent of injuries. Thirty-three percent of injuries were sustained by tweens and teens (ages 10 to 19).

The study looked only at zip line injuries, but a number of fatalities have made headlines in recent years, including a 12-year-old girl who plunged to her death at a North Carolina summer camp and an elderly man who met the same fate at a Christian family camp in Michigan.

Recreation in need of regulation?

Only a handful of states have developed safety standards for zip lines and similar activities. (West Virginia was the first to do so, as part of the state’s Amusement Rides and Amusement Attractions Safety Act.) The lack of uniform laws around safety features, inspections and other aspects of zip line operation means thrill-seekers should take care before buckling up and beaming down a mountainside.

Related: Are Indoor Trampolines Safe?

If you want to zip line, here’s are some ways to stay safe, according to experts at Nationwide Children’s Hospital:

  • Make sure the staff at any camp or facility that offers zip lining is well trained and can prove their zip lines meet industry safety standards.
  • Use proper safety equipment (a harness) and wear a helmet and gloves.
  • Follow all posted rules and instructions from the staff.
  • Don’t use homemade or backyard zip lines. These can be ordered as kits online or built from separately purchased parts. Either way, do-it-yourself zip lines are dangerous.

Related: 10 Safety Rules for ATVs and Snowmobiles