Past and current understanding of the pathophysiology of muscle cramps: why treatment of varicose veins does not relieve leg cramps.

Historically relevant hypotheses on the pathophysiology of muscle cramps are reviewed. Psychosomatic, static, vascular, myogenic and neural theories are highlighted from a clinician's point of view. Modern neurophysiologic research leaves little doubt that muscle cramp is caused by excitation of spinal motor neurones mediated by changes in presynaptic input. Nevertheless, obsolete theories and relative treatments stubbornly persist in clinical practice.