I am having a tiny area on a shin spasm or cramp, this is smaller than a quarter. They last a few seconds, and are frequent, but off and on. It is so painful it wakes me up at night. There is a blue bruise at the spot, and feels like a small lump. This has been two days. I have also driven more than usual, 5 days over 100 miles each the week before last, and last Friday about 150 miles. I am concerned, tomorrow I have to drive about 100 miles early in the day, and in the evening will be on a bus for 180 miles round trip. I am a 55 year old woman, obese, 5 foot 2, 204 pounds, arthritis but no othet major illnesses.