Biofeedback is one of the relaxation techniques commonly used in headache centers. Simply put, a machine is used to provide feedback to sufferers about muscle tension, which is associated with pain. Using that information patients learn to reduce the muscle tension in their bodies. With practice, this effect may be achieved without the machine. Studies have shown that people who learn biofeedback techniques can reduce pain by up to 50%-70%. For more information, contact The Biofeedback Certification Institute of America at (303) 420-2902.