In the 1970s, Indian-derived Yoga Therapy started to emerge as a more specific form of Yoga as Exercise. While Yoga as Exercise is aimed at maintaining and promoting health and fitness (the type of Yoga today commonly exercised), Yoga Therapy is the explicit use of Yoga exercises to alleviate or cure health conditions in the physical, emotional, and mental sphere.
Like Traditional Indian Yoga practices, Traditional Thai Yoga — aka Reusi Dat Ton, Rusie Datton, or Rue-Si Datton — knows more or less the same development: from a pure spiritual, meditative, and lifestyle discipline, it additionally developed as a health and fitness modality promoted by the Thai government.
In fact, at the end of the 20th century, the Watpo Medical Thai Massage School and the Institute of Thai Traditional Medicine (ITTM) both developed adapted Reusi Dat Ton exercise sets (the 18 Wat Pho exercises and the 15 ITTM Exercises) for the general public, which were meant as a promotion of Reusi Dat Ton in Thailand.
At the same time the idea was to supply the nation with safe and easy to do exercises for illness prevention, fitness, and stress-relief.
Nevertheless, the historical development of Reusi Dat Ton most likely departs from Indian Tantra Yoga, travelled across Nepal, then reached Tibet to be enriched by Tibetan esoteric Yogic practices, to finally reach Thailand, where it got influenced by local folk healing traditions and Traditional Chinese Medicine.
Still, even today, it’s clear that the Thai Yoga practice has a great deal of remarkable resemblances with Tibetan Yoga, both in the way it’s practiced and in the various poses and movements.
If we look at the name Reusi Dat Ton then it becomes more obvious how the practice in Thailand developed. Reusi Dat Ton in Thai language translates to “the Rishi (Sadhu, Seer, or Ascetic) who stretches himself”. Thus it refers to the sages or monks who used this modality to either stretch themselves (after meditation and to keep fit), or to strengthen themselves (for a better meditation practice), or who used certain positions, movements, and Asanas to experiment with the flow of Vital Life Energy in the body and how to use that energy for meditation or spiritual enlightenment practices.
Today, Reusi Dat Ton is also increasingly applied as a therapeutic modality — notably as physical therapy or physical rehabilitation — on its own terms, or in conjunction with Thai Massage therapy.
Nevertheless, this is not entirely new though: historically, Rusie Datton was apparently also meant to be used as a therapeutic practice, which included treating serious illnesses. The famous Samut Thai Khao Reusi Dat Ton book (composed in 1838) gives evidence of its (additional) therapeutic purpose.
Yet, that there are therapeutic effects of Reusi Dat Ton exercises seems rather to be a complementary thing — a side effect, as it were. Like it is in Indian Yoga. Traditionally, both Yogic disciplines specifically served as a support for a meditation practice to achieve self-realization and spiritual uplifting.
Reusi Dat Ton applied as therapy is in fact a “derived specialization.” This is not a “good or bad” thing though; Yogic practices keep on developing, and Thai Yoga as Therapy is just a different and “legit” way of using Reusi Dat Ton.