RESUMEN
Whirlpool hydrotherapy regulates the threshold through mechanical and thermal effect, promotes blood circulation, increases tissue malleability, and raises pain threshold, to relieve pain. Whirlpool can relieve osteoarthritis pain and improve joint stiffness, relieve myofascial pain and anxiety symptoms, relieve delayed-onset muscle soreness, reduce the sensitivity of pain after delivery. Combined with other physical therapy, it also significantly improves the swelling, pain and spasm of shoulder-hand syndrome. The main mechanism of whirlpool associates with improving the physiological environment of the local tissue, such as increasing the permeability of the vessel, to accelerate the metabolism of the pain media, reduce the nociceptive stimulation on the peripheral receptors; promoting the produce of analgesic substance; regulating the autonomic nervous system and pain gate. However, the specific treatment parameters are different in the studies, which need to be standardized.