Sonmud, literally, seon/sound (school) warp pathway is a sound martial art of Korean origin. It is a dynamic form of yoga, based on the control of breathing, movement and thought.
Perpetuated and taught by the Buddhist monks who were also preceptors of the young men of the warrior caste, the Hwarang, its origin is linked to that of Korean Buddhism. It was originally known as « keum kang yeong kwan ».
https://youtu.be/tzGmcA21y4E
here is the address for those who are interested: 101-5 Girim-ro, Yangbuk-myeon, Gyeongju, Gyeongsangbuk-do, Corée du Sud
http://sunmudo.com/