Trampoline park-related injuries have risen as the indoor jumping trend has spread.

A new study in Pediatrics found that the number of trampoline parks in the US have increased from 40 in 2011 to 280 in 2014. In correlation, trips to the emergency room due to injuries obtained at trampoline parks shot up from 580 in 2010 to about 7,000 in 2014, the latest year of the study.

They found that although injuries from home trampolines remained constant over the study period, ER visits due to trampoline parks have skyrocketed.

The injured patients at trampoline parks were more likely to be males around the age of 13.

Kathryn Kasmire of Connecticut Children’s Medical Center expressed that dislocations and sprains are among the most common trampoline park-related injuries. Some of the more serious injuries include skull and open leg fractures and spinal cord trauma. She said the injuries in some cases led to paralysis and surgery.

The International Association of Trampoline Parks (IATP) said in a statement it welcomes studies like this one that “provide a deeper understanding of safety issues.” The statement also noted that with industry growth the number of injuries isn’t surprising. “We believe that the positives of youth recreational sports far outweigh the negatives, and we are actively engaged at programs aimed at promoting the safety and well-being of jumpers who visit our member parks,” it said.

On the contrary, Dr. Katherine Leaming-Van Zandt, an emergency medicine physician at Texas Children’s Hospital, called the exponential growth of trampoline parks “concerning.”

She told CBS News that Texas Children’s continues to see “a substantial number of trampoline-related injuries, including abrasions, lacerations, sprains, fractures, and head and neck injuries.”

The American Academy of Pediatrics advises against trampoline use for all youth but says if children do use them, they should jump with caution. The academy said adult supervision is needed and that trampolines should also have proper padding.