Suprisingly accupunture with a heat lamp helps this.
Sit ups and excercises that strengthed to lower body help as well.
I was just reading that magnesium hydroxide helps by relaxing the muscles, so that they don't spasm. I've been trying to research magnesium hydroxide to see how it relates to magnesium... what form it is. They say it is in Milk of Magnesia. I don't want diarreah!