My musles in my legs and arms and part of my back twitch alot. After a days work, standing up, I get massive leg cramps. Mostly on my left leg, from my hamstring to my toes. First I took a week off from work, then two weeks. But when I return, so do the cramps, including my left thumb. The twitching is every day. Im not lacking vitamins or minerals, per blood test. Help.