The body-folding, sharp-elbowed techniques of Thai massage have been added to Unesco’s prestigious heritage list.

Originating in India and practised in Thailand for centuries, the massage was popularised when a special school opened in the 1960s to train massage therapists from around the world.

The addition of nuad Thai to Unesco’s list of “intangible cultural heritage” practices was “historic”, said the Thai delegate at the Unesco meeting in Bogotá, Colombia. “It helps promote the practice of Nuad Thai locally and internationally,” he said.

From upscale Bangkok spas and Phuket beachfronts to modest street-side shophouses, nuad Thai is ubiquitous, and an hour of the back-straightening discipline can cost as little as $5.

Doctors and monks were said to have brought these methods 2,500 years ago to Thailand, passing its secrets from master to disciple in temples and later within families.

Under Thailand’s King Rama III in the 19th century, scholars engraved their knowledge of the field onto the stones of the famed Wat Pho temple in Bangkok.

Its nuad Thai school, which has trained more than 200,000 massage therapists who practice in 145 countries, opened in 1962.

Today, a therapist at a top-end spa can charge around $100 an hour in Thailand, and two or three times more in London, New York or Hong Kong where the Thai massage brand is booming.

But the training is “demanding”, says Chilean Sari, a professional masseuse who travelled to Bangkok to learn the discipline.

“The technique is very precise; there are so many things to be aware of,” the 34-year-old said.

The teachings focus on directing blood circulation around problem areas to solve muscle aches – sometimes drawing winces from clients unaccustomed to the force applied.

Studies have shown it can help relieve back pain, headaches, insomnia and even anxiety.