Modern Thai massage practice is based on the assumption that the body is filled with ‘air’, which is inhaled into the lungs and is spread inside through 72000 roads, called ‘sen’, which healers handle manually. This is the main hypothesis of the Indian yoga. The ‘sen’ system is taken as physical or not physical structure, depending on the interpretation.
Traditional practice uses much more systematic theoretical system that identifies the impact of the massage techniques on 5 layers of the body (skin, tissue, ducts, bones, organs), associated with the 4 natural phenomenae (land, water, wind, fire). In this system, ‘sen’ is defined as tendons, ligaments, nerves and blood vessels, and element ‘air’ is understood as proper movement. This interpretation is taken from the Buddhist theories.