Is this really a muscle cramp?

Most muscle cramps are benign, but cramps that occur on exertion or in a patient with abnormal findings on physical examination or electromyography are usually caused by significant systemic disease. The most common systemic causes are metabolic diseases; central or peripheral nervous system diseases are less often responsible. Most systemic diseases that cause muscle cramps are amenable to specific treatment. If symptomatic treatment is desired, the first choice would appear to be stretching. If that is ineffective, carisoprodol (Rela, Soma, Soprodol), vitamin E, or verapamil hydrochloride (Calan, Isoptin) may be used. Quinine sulfate (Quine, Quinamm) is potentially toxic and may not be effective.