Every week, scores of young dancers take to Instagram to show off a physical feat that seems to defy the limits of human hip bones.

The #TiltTuesday trend features dancers stretching their legs into extreme contortions. Sometimes the photos merely attract likes or followers. Other times they can attract the attention of scouts, leading to audition opportunities or even sponsorship deals.

Instagram and YouTube are littered with images and videos of stretches such as the "side tilt," in which one leg is extended into a standing side split, often held at bizarre angles that extend past 180 degrees. Another popular pose, known sometimes as a "scorpion" involves one leg stretched out behind the dancer, bent and grasped behind the head like a tail poised to sting.

But some dance industry veterans say the trend is an unhealthy phenomenon that encourages young dancers to attempt risky movements that could bring about irreversible damage.

While some of the dancers performing these poses are professionally trained ballerinas, many are young amateurs in the earliest years of their dance training.

These young dancers pushing their bodies to achieve such complicated stretches or dangerous leaps are putting themselves at risk of ending their careers before they even begin, according to Paul Malek, a choreographer and artistic director at Australia's Transit Dance Company.

"Pushing these dancers so far past where they should be at ages eight, 10, 12 — they're actually wearing away what holds their hips together," Malek told Business Insider.

Tilt tuesday 💕 Featuring @phoenixsutch A photo posted by We❤️flexibility (@weheartflexibility) on May 31, 2016 at 2:49pm PDT May 31, 2016 at 2:49pm PDT

Malek has been an outspoken critic of the stunts and acrobatics he sees dancers perform in competitions and on social media. He said he has seen firsthand the effects that excessive stretching and unnecessary tricks — such as side tilts — can have on dancers' hips and joints.

Beyond the physical effects on young dancers' bodies, these trends have also warped their understanding of what dance is, Malek said. The tricks popularized on social media have introduced a narrow set of skills for dancers to aspire to — at the expense of the large range of movement contemporary dance encompasses.

"Instagram and social media is extremely, extremely to blame here in my opinion," he said. "I ask young dancers, 'Who are some of the great dancers in the world?' And they name 16-year-olds who have 300,000 followers on Instagram who can do a leg mount or scorpion really well."

The hunger for fame

Longtime dancers say the acrobatics trend in dance has been growing for years in tandem with the rise of social media and reality-TV dance shows. Leslie Scott, a dancer and choreographer who founded the nonprofit Youth Protection Advocates in Dance, has been researching and surveying young dancers about their social media habits for years.

Most young dancers keep up on the daily posts of Instagram dance "celebrities," who have racked up hundreds of thousands of followers through photos and videos of mind-boggling contortions and tricks, Scott told Business Insider. The result is that dancers now strive for fame, not mastery of dance.

Some of the most popular dancers like Maddie Ziegler — originally from the Lifetime show "Dance Moms" and currently a judge on Fox's "So You Think You Can Dance: Next Generation" — have attained a level of stardom that provokes instant reaction among their millions of followers.

When Ziegler posts a photo of an impressive leg lift or a pirouette, she accumulates hundreds of thousands of "likes" along with a slew of wistful comments: "How do you do that?" or "They make it look so easy," or "This hurts my heart."

Scott said she worries about the youngest generation of dancers, who now view these dance celebrities as role models. They may be setting themselves up for careers that are nearly impossible to achieve — both physically and realistically, she said.

"Many of them have shifted aspirations — occupational aspirations — from wanting to maybe go to college for dance or do something in dance therapy to wanting to be a dance celebrity," Scott said.

"They want to be like that, they want to look like that, they want to move like that. And they've also shared at times that they feel depressed and inadequate because they're not able to live up to that level of talent."

The physical consequences

#ballet#ballett#dance#dancing#love#gym#gymndstics#hashtag#instapic#instalove#split#oversplits#fun#tanzen#studio#balletbody#life#pointshoes A photo posted by Vera&Leonie (@pirouetteworld_) on Jul 2, 2016 at 3:41pm PDT Jul 2, 2016 at 3:41pm PDT

The hunger for fame and eagerness to perform wild stunts hasn't escaped the notice of the medical community. Ruth Solomon, a dance medicine expert and professor at the University of California at Santa Cruz, said she frequently treats injuries sustained from ambitious tricks and overstretching and is astounded by the extremes to which young dancers push their bodies.

Even a split can be harmful, she said, and many young dancers push their legs far past the standard 180-degree angle.

Although young bodies are durable and quick to heal from injuries, the constant repetition of such strenuous movements causes instability in hip sockets and can lead to severe pain in the joints — as well as long-term conditions like deformities, dysplasia, and labral tears, she said.

"That drives us up the wall. We really do not support any reason to do splits," Solomon told Business Insider. "Most young people who are not trained in technique prior to trying to do these kinds of things really are very vulnerable to hip problems especially."

The data appears to agree with Solomon's assessment — the number of dance-related injuries being treated in US emergency rooms annually has been climbing for years, according to one 2013 study by the Nationwide Children's Hospital's Center for Injury Research and Policy.

Between 1991 and 2007, the annual number of injuries in young dancers jumped by 37%, which is likely a wild underestimate, according to the study's lead author, Kristin Roberts. The study only had access to data from US emergency rooms and therefore didn't include injuries that were treated at home, by family doctors, or by private physiotherapists.

The causes of the increasing injury rate are even murkier, but social media trends, reality-TV shows, and video games that have helped popularize dance probably aren't too far off the mark, Roberts said.

Regardless of the root cause of the injuries, the popularity of these tricks defy all logic, Solomon said, especially because the solution is so simple: Stop performing movements the body isn't equipped to handle.

"I have no idea why this phenomenon has spouted up, except that it's a kind of entertainment without proper instruction," she said. "There are so many movements in the world that you could do. Why do something that might be deleterious?"