Muscles cramps are caused by prolonged spasms, or involuntary contraction of a muscle. Muscle cramps, especially those of the legs, are extremely common. Treatment is usually massage and stretching and adequate fluid intake, although in cases where cramps are frequent, medication may be recommended.
What is a muscle cramp?
A muscle cramp is an involuntarily and forcibly contracted muscle that does not relax. Any of the muscles under voluntary control (skeletal muscles) can cramp. Cramps of the extremities are very common, especially the legs and feet, and particularly the calf (often termed a "charley horse" cramp). When a muscle (or even a few fibers of a muscle) involuntarily contracts, it is called a spasm and becomes a cramp when the spasm is forceful and sustained.