NEW YORK (CBS 2) -- Yoga is synonymous with health and wellness, but in some cases it is causing pain and anguish.
Now, some are calling the practice unsafe, sparking a debate so fierce it's shaking the normally Zen community to its core.
Nonetheless, thousands of people who do yoga end up in emergency rooms each year. Yoga instructor Cathy Lilly says she tore three out of four tendons in her shoulder.
"It felt like my muscles were melting off my bones," said Roxy Emory.
"I strained my back after doing an 'upward facing dog,'" said Haemi Choi.
Yoga, with all its benefits, has been around for thousands of years. Criticizing the ancient practice may seem like bad karma, but now more and more students - even instructors - are questioning the safety of their beloved exercise.
"It is an epidemic," said Bill Broad.
Broad has been practicing yoga for 30 years. He's a New York Times reporter and author of The Science of Yoga, investigating it.
"It was sort of like you lit a fuse and a bomb went off," Broad said.
After five years of research, Broad says he determined certain yoga postures like head stands, shoulder stands and "the plow" are a big culprit when it comes to injuries - from dislocated hips to punctured lungs - even stroke.
"There are arteries that go through vertebrae. You start crunching around with them, you get clots, and they go to your brain and you have a stroke," Broad explained.
"There's two types of problems that people get into with yoga," said Dr. Michelle Carlson, and orthopedic surgeon with the Hospital for Special Surgery. "They irritate a condition they already have and... they cause an injury."
Carlson says she's seen in an increase in yoga injuries in recent years.
"It's just because yoga has become so popular," Carlson said.
It's that popularity that has others sounding the alarm about yoga injuries.
"People come to yoga... and they are not prepared physically or mentally to do these classes," said Glenn Black, who has been a yoga teacher for 40 years. "On the other end of that is the yoga... schools that say become a... teacher in a weekend."
Black says yoga is more than a fitness craze - it's a way of life. But packed classes combined with inexperienced teachers equals injuries.
Lilly says she couldn't agree more.
"I was doing 'warrior two,' a teacher from behind threw her arm around me, took her hand and pushed here and then [a] tendon got torn," said Lilly.
Carla Goldstein, Director of the Omega Institute for Holistic Studies, says yoga can be a very safe way to increase strength, flexibility, reduce stress, and so much more. You just have to pick wisely.
"Shopping for yoga is like shopping for any other important thing in your life, you really want to vet the teacher," said Goldstein.
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