The physiological effects include increased blood flow, circulation, and relaxation of muscle spasms and can also speed up the healing process. Used as a deep heat, (as opposed to surface heating of moist heat packs), by way of shortwave electromagnetic energy; it relaxes connective tissue and can increase range of motion, and can also reduce muscle spasms and cramping. It dilates blood vessels for improved circulation, stimulates white blood cell production, and increases metabolism and waste removal. It also helps to prevent adhesions and scar tissue.