Charley horse

Charley horse or muscle cramps

* involuntarily and forcibly contracted muscle that does not relax

* mild twitches that can last anywhere from a few seconds to a quarter of an hour or occasionally longer

* may recur mutliple times until it finally goes away

* may involve a part of the muscle, the entire muscle, or several muscles that usually act together

* skeletal muscles are most prone to cramping: calf, thigh, and arch of the foot are most notorious sites of cramps

* Causes: insufficient stretching before exercise, exercising in the heat, muscle fatigue, imbalance in the levels of electrolytes (sodium, potassium, chloride, calcium and phosphate in the blood)

* most resolve spontaneously within a few seconds to minutes

I woke up very early this morning with a cramp on my right leg. It must have been caused by poor sleeping position. I noticed I hadn't moved that leg the whole time so it must have caused that too. I did a quick research and got the information above---nothing serious, but it can be painful.