Ultrasound machines are a treatment modality used by physical therapists and chiropractors that utilize high or low frequency sound waves. These sound waves penetrate to cause deep tissue/muscle warming when used on constant setting, or can be used on a pulse to avoid heating tissue. Ultrasound can help reduce muscle tightness and spasms. The warming effect of the sound waves also cause vessel vasodilatation and increase circulation to the area that assists in healing. Ultrasound can also be used to push anti-inflammatory medications through the skin into the tissue.