From Rangjung Yeshe Wiki - Dharma Dictionnary
Vitality Element (srog)
- One of the four aspects of elemental divination on the basis of which calculations can be made concerning the status of the life-essence (bla) of sentient beings, which moves through the cycle of the lifespan principle (tshe rtsa) from the moment of birth until the moment of death. When the vitality is weak, ritual ransom of vitality (srog bslu ba) may be performed to restore its potency.
- The vitality element corresponding to a given year-sign is the very element governing the natural location of the corresponding animal. Thus, wood governing the eastern direction is the vitality element of the tiger and hare years, fire governing the south is the vitality element of the horse and snake years, iron governing the west is the vitality element of the bird and monkey years, water governing the north is the vitality element of the mouse and pig years, while earth, governing the intermediate directions is the vitality element of the ox, sheep, dog, and dragon years. In natal horoscope, predictions based on the type of relationship formed between a subject's vitality and destiny elements are important. See Part II, pp. 000-000, and Part IV, pp. 000-000. GD (from the Glossary to Tibetan Elemental Divination Paintings)