Yoga has been practised for thousands of years and its popularity is ever-growing.
Touted one of the best forms of exercise for flexibility, balance, and toning, as well as being celebrated for its spiritual benefits, it's no wonder hundreds of thousands Brits are taking part in classes each week.
To keep up with this demand, there are an increasing number of yoga teachers in the UK (over 10,000 according to recent statistics) — but now there's a warning they could be putting their hip health at risk.
Up to 460,000 people practice yoga every week in the UK, according to recent stats
Benoy Matthews, a leading UK-based specialist hip and knee physiotherapist, warns an increasing amount of his patients are yoga teachers.
Speaking to BBC, Matthews says he is seeing four to five yoga teachers per month, who are pushing their bodies into "prescribed" positions that they are not equipped to be in.
In most cases, his patients simply need advice on how to moderate these positions; at worst, they require surgery, including total hip replacements.
"People confuse stiffness and pain," the physio tells BBC. "If there is a pinching or blocking feeling in the groin, it shouldn't be ignored. You have to know your limits."
There are over 10,000 yoga teachers in the UK
"We all know about the health benefits of yoga - I practise it myself," he adds. "But, like anything, it can cause injury. We can't put it on a pedestal.
"I don't want to denounce yoga, after all it's been going for thousands of years. But you have to understand yourself.
"What's achievable for one might not be achievable for others. People tend to do the same set positions, rather than what's achievable for them.
"Ego might mean them trying to take a position 'all the way' to the end when they should just stop where it's comfortable.
"Just because the person next to you can reach all the way doesn't mean it's necessary, or desirable, to do the same."
Teachers are requiring keyhole surgery, and in some cases, total hip replacement
Mr Matthews — who has specialised in hips and knees for last eight out of his 22 years in physio — says problems can develop when yoga teachers aren't doing any other forms of exercise.
"They might be doing yoga six days a week and think that's enough, without doing any other kind of exercise, like cardio or cross training," he explains.
"It's like anything. If you do the same thing again and again, there can be problems. You need to mix it up in terms of the kind of exercise you do."
Mr Matthews said the yoga teachers he is seeing are young "40, 42", and more severe cases mean patients have to undergo keyhole surgery on their hips or an entire replacement.
Mr Matthews says he thinks new yoga teachers should be assessed to judge their mobility and "what their body is allowing them to do".
According to Finder, up to 460,000 Brits are taking part in yoga classes each week.
From Harper's Bazaar U.K.