A leg cramp is a pain that comes from a leg muscle. It is a muscle spasm, which occurs when a muscle contracts too hard. This is an involuntary contraction, meaning that the affected person has no control over how and when it occurs. It usually occurs in a calf muscle, below and behind a knee. The small muscles of the feet, or muscles elsewhere in the leg, are sometimes affected.
This is a companion discussion topic for the original article at https://patient.info/bones-joints-muscles/cramps-in-the-leg