has anyone felt and seen their heart beat in their upper arms, foot, leg, or back ? this might come and go from time to time. It wont last for more than 30 seconds at a time. if so, did you go to a doctor and did he say anything about it? just for clarification, say you are sitting at a computer, all of a sudden, your upper arm muscle would begin to twitch, and looking at it, you could see your heart beat move the muscle. it then would stop after 30 seconds. its a good feeling. i've read that it usually has to do with low body fat and very low blood pressure. i am just collecting some observations about it.