This is the agonising moment a woman's leg snapped when a yoga instructor pressed on her back.

The fitness enthusiast surnamed 'Le' had attended the stretching class in Wuhan City in Hubei, China, on January 18.

But instead of being relaxed, she suffered a leg fracture when the trainer tried to force her into a difficult pose by pushing her back while she was bent over on the mat.

Shocking CCTV footage shows the instructor applying pressure on Le, cracking her bone with a horrifying snap.

Le, still folded over in a resting pigeon pose, screamed in agony as the panicked yoga teacher patted her back and began typing on her phone to call for medical assistance.

Other startled students were seen looking behind as Le continued crying from the pain.

Le was rushed to a hospital, where it was found that she suffered a fracture on her left femur.

In an interview with local media, Le said her thigh had swollen and x-ray scans revealed that a protruding bone had pierced a muscle.

She said the yoga studio, which was popular and had many branches across China, compensated her for medical expenses but allegedly stopped giving money for her rehabilitation after she was discharged from the hospital.

She said: 'The yoga studio sent a text message later, saying, 'Our company will arrange the expenses for you' but now I don't know if they will pay for it later.'

Yoga, which originates from India, has attracted criticism in recent years due to its shady connections to cults, fraudsters, and sex fiends, such as Rajneesh, also known as Osho.

There are also risks to the exercises including muscle strains, ligament damage and repetitive stress injuries.