A handheld electric body massager is another way of saying Percussion Massage Gun.  Before you begin, plug in the unit if it is corded, or insert batteries if it is cordless. Turn on the massager and attach the necessary attachments as directed by the label. Unless your doctor advises otherwise, the first area to massage with the massager should be your shoulders and the back of your neck. Move the device from one shoulder to the other, as this is where the muscles are most tense. It should not be used in areas where bones protrude. Begin with the slowest setting and gradually increase the speed. Remember that most units can be adjusted over the course of a session, allowing the user to select the most comfortable setting. Then, massage your back, working your way down your spine. Instead of placing the device directly over your spine, massage the muscles on either side of it. Switch to the lower back, where the muscles are usually stiff, once you feel your muscles begin to relax. Then, move down to your buttocks, focusing on the hamstrings, which are frequently the source of lower back pain. Massage your calves and abdominal region, using the lowest setting for the latter. You can use the unit on your chest because stimulating the area around the heart improves blood flow and massaging the lymphatic nodes boosts immunity. Finally, work your way up to your arms and wrists.