By using high-frequency sound waves the deep tissues are heated and micro-massaged. This is the same technology used in Sonograms. Ultrasound can improve blood flow, reduce swelling, promote healing and relax muscles. I can also combine ultrasound with electrical stimulation to quickly reduce painful muscle spasms in the neck or back. Ultrasound penetrates several inches below the surface to get into the deeper parts of the muscles. By comparison, a heating pad will penetrate only millimeters. Most patients love ultrasound treatment because it is painless and very effective.