Hi, Overuse of a muscle, dehydration, muscle strain or simply holding a position for a prolonged period can cause a muscle cramp. In many cases, however, the cause isn t known. Although most muscle cramps are harmless, some may be related to an underlying medical condition, such as inadequate blood supply. Sometimes, it is postural because of compression of nerve roots. All you need to do is to keep changing your posture as much as possible. Magnesium, calcium and levocarnitine supplements are documented to help in large muscle cramps, you can try them as well. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Rohan Shanker Tiwari, Orthopedic Surgeon