Ultrasound therapy is used to minimize muscle pain and movement dysfunction. Therapeutic ultrasound uses sound waves to deliver deep heat to the treated tissues. The treatments may help reduce stiffness, swelling, and pain, increase circulation, and promote pain-free movement. Ultrasound therapy may be used alone or in conjunction with stretching, therapeutic massage, heat, or gentle chiropractic manipulation. Ultrasound therapy is a painless procedure, and many people find it relaxing.