Acupressure is an alternative medicine technique similar in principle to Acupuncture. It is based on the concept of life energy which flows through "meridians" in the body. In treatment, physical pressure is applied to trigger points with the aim of clearing blockages in these meridians. Pressure may be applied by hand, by elbow, or with various devices.
Some medical studies have suggested that acupressure may be effective at helping manage nausea and vomiting, or for helping lower back pain. According to Quackwatch acupressure is a dubious practice, and its practitioners use irrational methods.
There are several different instruments for applying nonspecific pressure by rubbing, rolling, or applying pressure on the reflex zones of the body. The acuball is a small ball made of rubber with protuberances that is heatable. It is used to apply pressure and relieve muscle and joint pain. The energy roller is a small cylinder with protuberances. It is held between the hands and rolled back and forth to apply acupressure.