Muscle relaxants are the group of drugs which relax muscles through acting on the central nervous system. The variety of such medicines is huge because there are a lot of situations why the muscle relaxants may be prescribed.
More often, an action of muscle relaxants is related to pain reducing and treating the spasms, if there are some injuries of muscles (sprains, strains). Other types of these drugs may be used only by doctors at the time of induction of general anesthesia or even in surgery (this type of muscle relaxant is given through the bloodstream).