I experience severe cramps and spasms in my calves, feet, forearms, hands, and jaw. There is no particular time when it is worse but is often triggered by a fine motor action like using a screw driver, power tools, tweezers,. I take calcium and large amounts of b-12 and magnesium daily. Without this it gets worse. My doctor has taken blood tests and nothing comes up. What else should I be doing? Stretching makes it worse.